Anil Fernando

Dr Anil Fernando


Reader in Video Communication
+44 (0)1483 684726
05 BB 01

Academic and research departments

Centre for Vision, Speech and Signal Processing (CVSSP).

Biography

My publications

Publications

Yip PY, Malcolm JA, Fernando WAC, Loo KK, Kodikara Arachchi H (2005) Joint source and channel coding for H.264 compliant stereoscopic video transmission, Canadian Conference on Electrical and Computer Engineering 2005 pp. 188-191
Stereoscopic video coding research has received considerable interest over the past decade as many 3D displays have been developed. Unfortunately, the vast amount of multimedia content needed to transmit or store a stereo image pair or video sequence has hindered its use in commercial applications. As H.264 offers significantly enhanced compression and a "network-friendly" feature, we have used a H.264 compliant stereoscopic video codec [9] to compress stereo video. The data partitioning (DP) mode in NAL unit of the H.264 codec is exploited for the use of joint source and channel coding (JSCC) taking channel qualities and reliabilities into account. In this paper, we propose a framework of using unequal error protection (UEP) based JSCC scheme on the H.264 compliant stereoscopic video transmission for additive white Gaussian noise (AWGN) channel. Different levels of error protection are assigned to different partitions based on their decoding importance. Performance comparisons are made against equal error protection (EEP) schemes. Results from the simulation show that using UEP schemes, the overall quality of the decoded main and auxiliary video sequence were clearly improved in comparison with the EEP scheme at good SNR but EEP schemes outperformed UEP schemes at low SNR values. © 2005 IEEE.
Malekmohamadi H, Fernando WAC, Kondoz AM (2013) Reduced reference metric for compressed stereoscopic videos, Electronics Letters 49 (11) pp. 701-702
A new reduced reference objective quality metric for stereoscopic video is proposed that incorporates spatial neighbouring information from grey-level co-occurrence matrices and edge properties. Extracted colour and depth features are combined unequally to maximise the performance of the proposed metric. The performance of this metric is validated through a series of subjective tests and the average correlation 0.82 is achieved when colour to depth importance ratio is near 0.80. © 2013 The Institution of Engineering and Technology.
Weerakkody WARJ, Fernando WAC, Kondoz AM (2009) Enhanced reconstruction algorithm for unidirectional distributed video coding, IET IMAGE PROCESSING 3 (6) pp. 329-334 INST ENGINEERING TECHNOLOGY-IET
Fernando WAC, Sharma S, Arachchi HK (2006) Adaptive joint source-channel coding for low-bit-rate conversational video communications with H.264 video codec, OPTICAL ENGINEERING 45 (9) ARTN 097007 SPIE-INT SOCIETY OPTICAL ENGINEERING
Fernando WAC, Canagarajah CN, Bull DR (2000) A unified approach to scene change detection in uncompressed and compressed video, IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 46 (3) pp. 769-779 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Fernando WAC, Canagarajah CN, Bull DR (2000) Fade, dissolve and wipe production in MPEG3 compressed video, IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS - 2000 DIGEST OF TECHNICAL PAPERS pp. 322-323 IEEE
Mallikarachchi T, Fernando A, Arachchi HK (2014) EFFICIENT CODING UNIT SIZE SELECTION BASED ON TEXTURE ANALYSIS FOR HEVC INTRA PREDICTION, 2014 IEEE INTERNATIONAL CONFERENCE ON MULTIMEDIA AND EXPO (ICME) IEEE
Fernando WAC, Canagarajah CN, Bull DR (2000) Fade-in and fade-out detection in video sequences using histograms, ISCAS 2000: IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS - PROCEEDINGS, VOL IV pp. 709-712 IEEE
Martinez JL, Kalva H, Fernando WAC, Cuenca P, Quiles FJ (2009) EFFICIENT WZ-TO-H.264 TRANSCODING USING MOTION VECTOR INFORMATION SHARING, ICME: 2009 IEEE INTERNATIONAL CONFERENCE ON MULTIMEDIA AND EXPO, VOLS 1-3 pp. 1394-1397 IEEE
De Silva DVSX, Fernando WAC, Worrall ST (2010) 3D video communication scheme for error prone environments based on motion vector sharing, 3DTV-CON 2010: The True Vision - Capture, Transmission and Display of 3D Video
The Emergence of three dimensional (3D) video applications, based on Depth Image Based Rendering (DIBR) has brought about new dimensions to the video transmission problem, due to the need to transmit additional depth information to the receiver. Until the transmission problem of 3D video is adequately addressed, consumer applications based on 3D video will not gain much popularity. Exploiting the unique correlations that exist between the color and their corresponding depth images, will lead to more error resilient video encoding schemes for 3D video. In this paper we present an error resilient 3D video communication scheme that exploits the correlation of motion vectors in color and depth video streams. The presented method achieves up to 0.8 dB gain for color sequences and up to 0.7 dB gain for depth sequences over error prone communication channels. © 2010 IEEE.
Dung DN, Fernando WAC (2002) Unequal error protection for H.26L video transmission, 5TH INTERNATIONAL SYMPOSIUM ON WIRELESS PERSONAL MULTIMEDIA COMMUNICATIONS, VOLS 1-3, PROCEEDINGS pp. 821-825 IEEE
Fernando WAC, Canagarajah CN, Bull DR (2000) Statistical feature extraction from compressed video sequences, 2000 INTERNATIONAL CONFERENCE ON IMAGE PROCESSING, VOL III, PROCEEDINGS pp. 925-928 IEEE
Kamolrat B, Fernando WAC, Mrak M (2010) Adaptive motion-estimation-mode selection for depth video coding, Proceedings of IEEE International Conference on Acoustics, Speech and Signal Processing pp. 702-705
An effective representation of 3D video in future 3D-TV systems consists of monoscopic video (colour component) and associated per-pixel depth information (depth component). As depth component indicates relative distance between objects within the scene and a camera, pixel values change not only when objects move in vertical and horizontal directions but also when they move in a depth direction. Instead of predicting motion of objects in two directions as appearing in traditional video codecs, three-dimensional block matching (3D-BM) achieves more accurate motion estimation in depth video coding. However overall performance of 3D-BM exceeds that of the traditional two-dimensional block matching (2D-BM) only at high bit rate. In this paper, an adaptive 2D-3D BM selection algorithm is introduced to compromise performance of 2DBM and 3D-BM. The Lagrangian optimisation algorithm is applied to select motion estimation mode at a block level. The experiment results reveal that the proposed adaptive motion-estimation-mode selection can improve the performance of 3D-BM at low bit rate while advantages of 3D-BM are preserved at high bit rate.
Arachchi HK, Fernando WAC (2003) An intelligent rate control algorithm to improve the video quality at scene transitions for off-line MPEG-1/2 encoders, IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 49 (1) pp. 210-219 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Fernando WAC, Canagarajah CN (2004) Wipe scene change detection and classification in video sequences, JOURNAL OF ELECTRONIC IMAGING 13 (2) pp. 362-375 IS&T & SPIE
Malekmohamadi H, Fernando A, Kondoz A (2014) A new reduced reference metric for color plus depth 3D video, Journal of Visual Communication and Image Representation
A new reduced reference (RR) objective quality metric for 3D video is proposed that incorporates spatial neighboring information. The contrast measures from gray level co-occurrence matrices (GLCM) for both color and depth sections are main parts of spatial information. Side information is extracted from edge properties of reference 3D video and sent through an auxiliary channel. The other important factor in the proposed metric is the unequal weight of color and depth sections, which can maximize the performance of the proposed metric for some specific values. Performance of the proposed metric is validated through series of subjective tests. For validations, compression and transmission artifacts are considered. The average correlation of the proposed metric and subjective quality scores is 0.82 for compressed 3D videos when color to depth importance ratio is near 0.8. This measure for transmitted 3D videos is 0.857 for the same value of color to depth importance ratio. © 2013 Elsevier Inc. All rights reserved.
Fernando WAC, Canagarajah CN, Bull DR (2000) A unified approach to scene change detection in uncompressed and compressed video, IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS - 2000 DIGEST OF TECHNICAL PAPERS pp. 350-351 IEEE
Weerakkody WARJ, Fernando WAC, Martínez JL, Cuenca P, Quiles F (2007) MAP decoder design for distributed video coding in error prone wireless channels, ICIIS 2007 - 2nd International Conference on Industrial and Information Systems 2007, Conference Proceedings pp. 379-382
In this paper MAP (Maximum a Posteriori) algorithm in the turbo decoder has been modified to use with the Distributed Video Coding (DVC) decoder, when the parity bit stream is transmitted over a noisy/fading channel. The proposed modification allows independent probability distributions for the systematic and parity components at the input to the turbo decoder. The designed MAP decoder has been tested with an AWGN and with a WCDMA channel. ©2007 IEEE.
Arachchi HK, Fernando WAC, Edirisinghe EA (2006) Novel scanning order for improving the bit rate performance of ZTE video coding, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES E89A (11) pp. 2977-2984 IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG
Weerakkody WARJ, Fernando WAC, Adikari ABB (2007) Distributed video coding of Wyner-ziv frames using trellis coded modulation, Canadian Conference on Electrical and Computer Engineering pp. 314-317
Distributed Video Coding (DVC) is known as an emerging video coding technique, which primarily has a modified complexity balance in the encoder and decoder, in contrast to its traditional competitors. In DVC, we have a very simple low cost encoder which is an ideal feature for applications involving a large number of video capturing points located remotely and a centralized shared decoder. In this paper, we introduce a novel approach for DVC, using Turbo Trellis Coded Modulation (TTCM) to generate the parity information at the encoder to be sent over the channel and then to decode the parity with the side information at the decoder. The side information is generated using key frames passed to the decoder by the use of a pixel interpolation technique. TCM symbols are formed using the side information and the parity bit stream which are fed to the TTCM decoder. The decoded output is used to reconstruct the final video sequence. The results are compared with a turbo coding based DVC and it is evident that the proposed method outperforms its turbo code based counterpart by a significant margin.
Perera R, Fernando A, Arachchi HK, Imran MA (2015) Adaptive Modulation and Coding based Error Resilience for Transmission of Compressed Video, 2015 INTERNATIONAL WIRELESS COMMUNICATIONS & MOBILE COMPUTING CONFERENCE (IWCMC) pp. 1127-1132 IEEE
Badem MB, Fernando WAC, Weerakkody WARJ, Yasakethu SLP, Kondoz AM (2008) Region-of-Activity Based Coding for Transform Domain DVC, 24th International Conference on Information and Automation for Sustainability pp. 154-157 IEEE
Distributed video coding (DVC) has been widely acclaimed as an emerging video coding technology with immense potential for use in video surveillance systems due to its flexibility for designing extremely low complex video encoders. In this paper, we propose a novel modified framework for the DVC codec considering a region-of-activity based coding algorithm. The frames will be split into a sequence of regions based on the activity level that reflect the error distribution in the side information. The macro blocks will be re-ordered to concatenate the unevenly distributed errors and form new blocks for turbo coding to improve the efficiency of the puncturing process. The performance of the proposed technique is verified for three standard test video sequences and up to 21% bit rate saving is demonstrated.
Fernando WAC, Canagarajah CN, Bull DR (1999) Automatic detection of fade-in and fade-out in video sequences, Proceedings - IEEE International Symposium on Circuits and Systems 4
A common video indexing technique is to segment video shots by identifying scene changes and then to extract features. This paper discusses a novel algorithm for detecting fade-in and fade-out using statistical features of both luminance and chrominance signals. The ratio between incremental change in the mean of the luminance signal to the chrominance (average sum of Cr and Cb) is considered to identify fade-in and fade-out. Results show that the algorithm is capable of detecting all fade regions accurately even the video sequence contains other special effects.
Adikari ABB, Fernando WAC, Arachchi HK, Weerakkody WARJ (2006) Multiple side information streams for distributed video coding, ELECTRONICS LETTERS 42 (25) pp. 1447-1449 INSTITUTION ENGINEERING TECHNOLOGY-IET
Kamolrat B, Fernando WAC, Mrak M (2008) 3D motion estimation for depth information compression in 3D-TV applications, ELECTRONICS LETTERS 44 (21) pp. 1244-1245 INST ENGINEERING TECHNOLOGY-IET
Danish E, De Silva V, Fernando A, De Alwis C, Kondoz A (2014) Content aware resource allocation in OFDM systems for energy efficient video transmission, Digest of Technical Papers - IEEE International Conference on Consumer Electronics pp. 456-457
For OFDM channels, we propose a content-aware subcarrier allocation scheme for multiuser video transmission that maximizes user perceived quality while minimizing power consumption. The scheme utilizes utility function-based genetic algorithms to solve the multi-objective optimization problem. It significantly outperforms existing methods in terms of perceived quality and consumed power. © 2014 IEEE.
Yasakethu SLP, Hewage CTER, Fernando WAC, Kondoz AM (2008) Quality analysis for 3D video using 2D video quality models, IEEE Transactions on Consumer Electronics 54 (4) pp. 1969-1976
Kodikara H, Fernando WAC (2005) PSO based bit rate optimization for MPEG-1/2 video coding, 2005 International Conference on Image Processing (ICIP), Vols 1-5 pp. 2345-2348 IEEE
Martinez JL, Fernandez-Escribano G, Kalva H, Fernando WAC, Cuenca P (2009) Wyner-Ziv to H.264 Video Transcoder for Low Cost Video Encoding, IEEE T CONSUM ELECTR 55 (3) pp. 1453-1461 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
This paper proposes a Wyner-Ziv / H.264 transcoder that enables low cost video applications. The proposed solution supports video encoding on resource constrained devices such as disposable video cameras, network camcorders and low cost video encoders. This approach is based on reducing encoding resource requirements on a device by using Wyner-Ziv video encoding. The system shifts the burden of complexity away from the encoder, for example to a network node, where a transcoder efficiently converts WZ encoded video to H.264 by reusing the information from the WZ decoding stage. The transcoded H.264 video is require fewer resources than WZ decoding and therefore reduces the complexity of decoding. The complexity of encoding and playback ends of video applications is thus reduced enabling new class of. consumer application. The paper is focused on reducing the complexity of the macro-block mode coding decision process carried out in H.264 encoding stage of the transcoder. Based on a data mining process, the approach replaces the high complexity H.264 mode decision algorithm by a faster decision tree. The proposed architecture reduces the battery consumption of the end-user devices and the transcoding time is reduced by 86% with negligible rate-distortion loss.
Fernando WAC, Rajatheva RMAP (1998) Performance of COFDM for LEO satellite channels in global mobile communications introduction, 48TH IEEE VEHICULAR TECHNOLOGY CONFERENCE, VOLS 1-3 pp. 1503-1507 IEEE
Weerakkody WARJ, Fernando WAC, Adikari ABB (2006) Distributed Video Coding of pixel interleaved Wyner-Ziv frames, 2006 International Conference on Industrial and Information Systems, Vols 1 and 2 pp. 525-528 IEEE
Fernando WAC, Canagarajah CN, Bull DR (1999) Automatic detection of fade-in and fade-out in video sequences, ISCAS '99: PROCEEDINGS OF THE 1999 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOL 4 pp. 255-258 IEEE
Fernando WAC, Canagarajah CN, Bull DR (2001) Scene change detection algorithms for content-based video indexing and retrieval, ELECTRONICS & COMMUNICATION ENGINEERING JOURNAL 13 (3) pp. 117-126 IEE-INST ELEC ENG
Chatterjee S, Fernando WAC, Wasantha MK (2003) Adaptive modulation based MC-CDMA systems for 4G wireless consumer applications, IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 49 (4) pp. 995-1003 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Weerakkody WARJ, Fernando WAC, Adikari ABB (2007) Bitplane based Wyner-Ziv coding using unequal error protection, Canadian Conference on Electrical and Computer Engineering pp. 1192-1195
In this paper, we discuss a novel approach to Distributed Video Coding (DVC) using bitplane based unequal error protection. Distributed video coding (DVC) has recently attracted a vast amount of attention from the video coding community all around the world, since it could prove very well suited for some applications where low-complexity encoders are a must. The primary feature of DVC is its modified complexity balance in the encoder and decoder, in contrast to its traditional competitors. When considering each pixel of the frame, out of the 8 bits it constitutes, each bit position has a different significance decreasing gradually from the MSB to the LSB. Therefore a scheme which protects the initial bitplanes better would undoubtedly be desirable. Here we propose to protest each bitplane considering its significance using variable memory length in the encoder. Since increasing the memory length results in higher computational complexity, the optimum mix of the memory length is to be evaluated for the codec to operate within the conceptual restrictions of low-complex encoder in DVC. In this paper, the proposed codec is compared for performance with another DVC codec which uses a fixed memory length over the whole sequence with comparable complexity. Simulation results show that the proposed method outperforms its fixed memory length counterpart t by a significant margin.
Adedoyin S, Fernando WAC, Karim HA, Hewage CTER, Kondoz AM (2008) Scalable Multiple Description Coding with Side Information Using Motion Interpolation, IEEE T CONSUM ELECTR 54 (4) pp. 2045-2052 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Ren K, Fernando WAC, Calic J (2008) Optimising Video Summaries Using Unsupervised Clustering, PROCEEDINGS ELMAR-2008, VOLS 1 AND 2 pp. 451-454 CROATIAN SOCIETY ELECTRONICS MARINE
De Alwis C, De Silva V, Kodikara Arachchi H, Fernando A, Kondoz A (2014) On the multicast of delay sensitive data in erasure networks using proactical network coding,
Rajakaruna T, Fernando W, Calic J (2010) Facilitating Motion-Based Vision Applicatons By Combined Video Analysis And Coding, Proceedings of IEEE Conference on Acoustics Speech and Signal Processing pp. 1102-1105 IEEE
In order to jointly optimise the quality of video coding on one hand and video analysis on the other, this paper proposes a novel approach to enhance the reusable information content in compressed video domain. By introducing a hierarchical content driven motion estimation mechanism at the encoder, complemented by a statistical prediction of region-of-interest, this approach reduces the complexity and yet increases robustness of the compressed domain vision analysis applications. Taking the object tracking application as an example, we demonstrate that the motion vectors generated by the proposed method can be directly used to extract object information, achieving tracking performance comparable with a pixel domain approach. In addition, we show that the incurred rate distortion (RD) overheads and the effect on encoder complexity are minimal, especially when compared to the reduction of processing required for video analysis targeting a wide spectrum of computer vision applications.
Adikari ABB, Fernando WAC, Weerakkody WARJ, Kondoz A, Martinez JL, Cuenca P (2008) DVC Based Stereoscopic Video Transmission in a Mobile Communication System, NGMAST 2008: SECOND INTERNATIONAL CONFERENCE ON NEXT GENERATION MOBILE APPLICATIONS, SERVICES, AND TECHNOLOGIES, PROCEEDINGS pp. 439-443 IEEE COMPUTER SOC
de Alwis C, Arachchi HK, Fernando A, Pourazad M (2014) Content and Network-Aware Multicast Over Wireless Networks, 2014 10TH INTERNATIONAL CONFERENCE ON HETEROGENEOUS NETWORKING FOR QUALITY, RELIABILITY, SECURITY AND ROBUSTNESS (QSHINE) pp. 122-128 IEEE
De Silva DVSX, Fernando WAC, Worrall ST (2010) Intra mode selection method for depth maps of 3D video based on rendering distortion modeling, IEEE Transactions on Consumer Electronics 56 (4) pp. 2735-2740
A technique to minimize distortions in synthesized virtual views, while encoding depth maps that are used in Depth Image Based Rendering (DIBR) applications is proposed. Depth maps are not viewed by end users, but are used for virtual view generation. Therefore, it is important to compress depth maps in a way that it minimizes distortion in views rendered with them. In doing so, it would be possible to generate high quality virtual views using compressed depth maps. Firstly, an error model to approximate rendering distortion caused by disparity changes is proposed. Thereafter, this error model is used at the encoding mode selection stage of coding depth maps. Experimental results illustrate an average bit rate saving of 19%-76%, compared with the mode selection method, which is based on minimizing pixel errors only of the depth map. Further, encoding depth maps with the proposed technique improves the overall visual quality of rendered views. © 2006 IEEE.
Shahriari A, Fernando WAC, Arachchi HK (2006) Adaptive Video Concealment using Neural Networks for H.264 Based Video Coding., CCECE pp. 2041-2044 IEEE
Transmission errors are unavoidable in almost all state-of-the-art communication systems. Due to the predictive nature of the syntax elements and the use of variable length coding in video coding techniques, even a single bit error could render a large portion of the bit stream undecodable. Therefore, some parts of a picture may not be able to reconstruct correctly. Due to spatial temporal prediction, these errors can be propagated spatial and temporal directions forming annoying visual artifacts. Therefore, error concealment is a key requirement in almost all video applications. In this paper, we propose a fully receiver based adaptive error concealment algorithm using neural networks for video applications. A previously trained neural network is fine tuned using correctly received motion vectors and the corrupted motion vectors are predicted block by block using this network. Experimental results show that the proposed algorithm improves the picture quality significantly.
Badem MB, Fernando WAC, Martinez JL, Cuenca P (2009) AN ITERATIVE SIDE INFORMATION REFINEMENT TECHNIQUE FOR TRANSFORM DOMAIN DISTRIBUTED VIDEO CODING, ICME: 2009 IEEE INTERNATIONAL CONFERENCE ON MULTIMEDIA AND EXPO, VOLS 1-3 pp. 177-180 IEEE
Hewage CTER, Ahmad Z, Worrall ST, Dogan S, Fernando WAC, Kondoz A (2009) Unequal Error Protection for Backward Compatible 3-D Video Transmission over WiMAX, ISCAS: 2009 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS 1-5 pp. 125-128 IEEE
Weerakkody WARJ, Fernando WAC, Adikari ABB, Rajatheva RMAP (2006) 4-PSK TTCM for Wyner-Ziv frame coding in DVC, IEICE ELECTRONICS EXPRESS 3 (8) pp. 178-183 IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG
Fernando WAC, Peiris KPCD (2002) Analysis of a blind code acquisition scheme for WCDMA systems in relatively fast fading channels, 5TH INTERNATIONAL SYMPOSIUM ON WIRELESS PERSONAL MULTIMEDIA COMMUNICATIONS, VOLS 1-3, PROCEEDINGS pp. 1138-1141 IEEE
Muraleetharan K, Fernando WAC, Weerakkody WARJ, Rajatheva RMAP (2007) MIMO wireless channel for video communications using Distributed Video Coding, 2007 CANADIAN CONFERENCE ON ELECTRICAL AND COMPUTER ENGINEERING, VOLS 1-3 pp. 1610-1613 IEEE
De Silva DVSX, Fernando WAC, Yasakethu SLP (2009) Object Based Coding of the Depth Maps for 3D Video Coding, IEEE T CONSUM ELECTR 55 (3) pp. 1699-1706 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
The emergence of three dimensional (3D) video applications, based on Depth Image Based Rendering (DIBR) has brought lip more requirements of bandwidth, due to the need of depth information. This additional bandwidth requirement need to be tackled to enable the widespread of 3D video applications based on DIBR. Exploiting visual correlations between the color image and the depth image, in depth image coding, will reduce the requirement of high bandwidth required to transmit the additional depth information. In this paper, an object based depth image coding technique is presented which is suitable for low bit rate 3D-TV applications that are based on Depth Image Based Rendering. The proposed method achieves at most 50% bit rate reduction at low bit rates.
De Alwis C, Kodikara Arachchi H, De Silva V, Fernando A, Kondoz A (2012) Robust video communication using Random Linear Network Coding with Pre-Coding and Interleaving, Proceedings - International Conference on Image Processing, ICIP pp. 2269-2272
With the increasing popularity of online video streaming and broadcasting applications, video transmission has become the most bandwidth consumed application in the Internet. Unless resource utilisation is further optimised, existing networks would not be able to accommodate the forecasted demand for high volume video traffic. Random Linear Network Coding (RLNC) is a promising approach to increase the network throughput and robustness in order to facilitate high volume traffic. However, the performance gain obtained using RLNC decreases when the network packet loss rate increases. In response, this paper proposes to incorporate RLNC with a combined interleaving and a coding technique to improve the effectiveness of generating redundant packet combinations over classical RLNC to enhance the robustness against packet losses. Simulation results illustrate that the proposed method improves the probability of recovering lost data over the classical RLNC and the video transmission simulation results exhibit up to 5dB increase in PSNR and up to 14% increase in VQM utilising the same network resources at the same network conditions. © 2012 IEEE.
Adikari ABB, Fernando WAC, Arachchi HK, Weerakkody WAR (2007) Wyner-ziv coding with temporal and spatial correlations for motion video, 2006 Canadian Conference on Electrical and Computer Engineering, Vols 1-5 pp. 1388-1391 IEEE
Arachchi HK, Fernando WAC (2002) Effect of dissolve transitions in rate control of MPEG-1/2 video, IEEE 56TH VEHICULAR TECHNOLOGY CONFERENCE, VTC FALL 2002, VOLS 1-4, PROCEEDINGS pp. 1427-1431 IEEE
Areia JD, Pereira F, Fernando WAC (2008) Impact of the Key Frames Quality on the Overall Wyner-Ziv Video Coding Performance, PROCEEDINGS ELMAR-2008, VOLS 1 AND 2 pp. 467-470 CROATIAN SOCIETY ELECTRONICS MARINE
Kulupana G, Talagala DS, Arachchi HK, Fernando A (2015) Resource Allocation for Cloud-based Social TV Applications Using Particle Swarm Optimization, 2015 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS (ICC) pp. 1226-1231 IEEE
Yasakethu SLP, Fernando WAC, Kondoz A (2009) Evolution strategy based rate controlling for off-line video coding, ELECTRONICS LETTERS 45 (4) pp. 204-U22 INST ENGINEERING TECHNOLOGY-IET
Kulupana G, Talagala DS, Arachchi HK, Fernando A (2015) Optimized Resource Distribution for Interactive TV Applications, 2015 IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS (ICCE) pp. 70-71 IEEE
Fernando WAC, Min LL (2005) H.264 video codec for HDTV terrestrial transmission, ICCE: 2005 INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS, DIGEST OF TECHNICAL PAPERS pp. 9-10 IEEE
Danish E, Silva V, Fernando A, Alwis C, Kondoz A (2014) Content-aware resource allocation in OFDM systems for energy-efficient video transmission, IEEE Transactions on Consumer Electronics 60 (3) pp. 320-328
© 1975-2011 IEEE.Demand on multimedia content by consumers' handheld devices over wireless channels is on the increase. In view of the accelerated trend towards consumption of high quality video, power utilization by mobile devices is expected to excessively increase. Hence, it becomes equally important to advance more efficient power minimization techniques, in light of the short battery life in portable devices. However, power minimization algorithms that adopt consumers' perceptual quality of video have not received adequate research. This paper proposes a joint optimization of energy and quality requirements in a multiuser orthogonal frequencydivision multiplexing environment. A multi-objective optimization problem is formulated with the aim to identify bitrate allocations among users such that total power is minimized, and average quality is maximized. For this, a content-aware and energy-efficient resource allocation scheme (CaERAS) is proposed based on genetic and greedy algorithms. Simulation results show that CaERAS, as a lowcomplexity scheme, outperforms comparable methods in terms of efficiency and selectivity of suboptimal solutions. It is shown to acquire a suboptimal solution in as low as 0.0025 of the search space in previous methods. Also, a significant average saving of 85.66% in required energy is observed in broadcast transmission as opposed to unicast transmission.
Pholyiam A, Ahmed KM, Tsuji H, Fernando WAC (2003) Joint estimation of propagation delay and direction of arrival of multipath signals, 57TH IEEE VEHICULAR TECHNOLOGY CONFERENCE, VTC 2003-SPRING, VOLS 1-4, PROCEEDINGS pp. 529-533 IEEE
Adikari ABB, Fernando WAC, Weerakkody WARJ (2007) Side information improvement in DVC with two side information streams and 3D motion refinement, Canadian Conference on Electrical and Computer Engineering pp. 32-35
Distributed Video Coding (DVC) has become increasingly popular in recent times among the researchers in video coding due to its attractive and promising features. DVC primarily has a modified complexity balance between the encoder and decoder, in contrast to conventional video codecs. Side information generation, carried out at the decoder, is a major function in the DVC coding algorithm and plays a key-role in determining the performance of the codec. In this paper, a novel enhanced algorithm is proposed for the side information generation process where the side information is evolved over the processing of each bit plane. Simulation results of the proposed technique depict a consistent improvement in performance in comparison to the state-of-the-art in pixel domain DVC. ©2007 IEEE.
Arachchi HK, Fernando WAC (2005) H.264/AVC in mobile environment: a review, OPTICAL ENGINEERING 44 (9) ARTN 097006 SPIE-INT SOCIETY OPTICAL ENGINEERING
De Silva DVSX, Ekmekcioglu E, Fernando WAC, Worrall ST (2011) Display Dependent Preprocessing of Depth Maps Based on Just Noticeable Depth Difference Modeling, IEEE JOURNAL OF SELECTED TOPICS IN SIGNAL PROCESSING 5 (2) pp. 335-351 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Adikari ABB, Fernando WAC, Arachchi HK, Weerakkody WARJ (2006) Sequential motion estimation using luminance and chrominance information for distributed video coding of Wyner-Ziv frames, ELECTRONICS LETTERS 42 (7) pp. 398-399 INSTITUTION ENGINEERING TECHNOLOGY-IET
Fernando WAC, Canagarajah CN, Bull DR (1999) DFD based scene segmentation for H.263 video sequences, Proceedings - IEEE International Symposium on Circuits and Systems 4
Content based indexing and retrieval of video is becoming increasingly important in many applications. Identifying scene changes and special effects in a video scene is an essential pre-requisite for indexing. In this paper, a sudden scene change detection algorithm for H.263 video sequences is proposed. This method uses the number of intra-coded macroblocks and Displaced Frame Difference (DFD) signal of the video signal. Experimental results show that the performance of this algorithm is independent of the encoder threshold. Furthermore, this algorithm is capable of detecting abrupt scene changes accurately even the video sequence contains special effects.
Martinez JL, Fernandez-Escribano G, Kalva H, Fernando WAC, Garrido A (2009) Wyner-Ziv to H.264 video transcoder for mobile telephony, Digest of Technical Papers International Conference on Consumer Electronics pp. 309-310 IEEE
Wyner-Ziv (WZ) coding has been receiving attention from the research community as it offers a more symmetric complexity in video communication by reducing the complexity of video encoding. This encoding paradigm, however, increases the complexity of video decoding. This paper presents a novel video communication architecture that exploits the low complexity WZ encoding without being burdened by high complexity WZ decoding. At the core of the proposed architecture is a WZ to H.264 transcoder that converts WZ video to H.264 to reduce the amount of resources necessary for decoding. This architecture enables low complexity encoding and decoding on mobile devices. Using very simple WZ encoders and H.264 decoders, a communication system will only need very low complexity devices at both the sender and receiver sides. Such low complexity communication devices are highly desirable for practical consumer applications. The paper also presents the low complexity algorithms for WZ to H.264 transcoding. The time reduction of the improved WZ/H.264 transcoder offers a very acceptable 86% complexity reduction with negligible Rate-Distortion loss.
Adedoyin S, Fernando WAC, Kondoz AM (2010) Scalable MDC for 3D Stereoscopic Video using motion vector encoding, Multimedia and Expo (ICME), 2010 IEEE International Conference on pp. 1718 -1723-1718 -1723
Adedoyin S, Fernando WAC, Aggoun A (2007) A joint motion & disparity motion estimation technique for 3D integral video compression using evolutionary strategy, IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 53 (2) pp. 732-739 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
De Silva V, Fernando A, Worrall S, Kodikara H, Kondoz A (2011) Sensitivity Analysis of the Human Visual System for Depth Cues in Stereoscopic 3-D Displays, IEEE TRANSACTIONS ON MULTIMEDIA 13 (3) pp. 498-506 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Foomooljareon P, Fernando WAC, Ahmed KM (2003) PAPR reduction of OFDM systems using input sequence envelope scaling, 57TH IEEE VEHICULAR TECHNOLOGY CONFERENCE, VTC 2003-SPRING, VOLS 1-4, PROCEEDINGS pp. 1243-1247 IEEE
Fernando WAC, Canagarajah CN (2001) Scene adaptive video encoding for MPEG and H.263+video, IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 47 (4) pp. 760-769 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Malekmohamadi H, Fernando A, Kondoz A (2014) A new reduced reference metric for color plus depth 3D video, Journal of Visual Communication and Image Representation 25 (3) pp. 534-541
A new reduced reference (RR) objective quality metric for 3D video is proposed that incorporates spatial neighboring information. The contrast measures from gray level co-occurrence matrices (GLCM) for both color and depth sections are main parts of spatial information. Side information is extracted from edge properties of reference 3D video and sent through an auxiliary channel. The other important factor in the proposed metric is the unequal weight of color and depth sections, which can maximize the performance of the proposed metric for some specific values. Performance of the proposed metric is validated through series of subjective tests. For validations, compression and transmission artifacts are considered. The average correlation of the proposed metric and subjective quality scores is 0.82 for compressed 3D videos when color to depth importance ratio is near 0.8. This measure for transmitted 3D videos is 0.857 for the same value of color to depth importance ratio. © 2013 Elsevier Inc. All rights reserved.
Weerakkody WARJ, Fernando WAC, Adikari ABB, Rajatheva RMAP (2006) Distributed video coding of Wyner-Ziv frames using turbo trellis coded modulation, Proceedings International Conference on Image Processing, Vols 1-7 pp. 257-260 IEEE
Weerakkody WARJ, Fernando WAC, Adikari ABB (2007) Unidirectional distributed video coding for low cost video encoding, IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 53 (2) pp. 788-795 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Fernando A, Wasantha MK, Ahmed KM (2003) Here to stay, IEE Communications Engineer 1 (3) pp. 44-47
The role of adaptive modulation techniques in the wireless networks of the future is discussed. Adaptive modulation permits the good coded orthogonal frequency division multiplexing (COFDM) channels to be allocated more sophisticated modulation techniques to increase the data throughput, while poor channels can use basic modulation techniques. Adaptive modulation, which adapts the transmission scheme to current channel characteristics, is used to achieve robust and spectrally efficient communication over multipath fading channels. The results indicate that the dynamic switching of modulation format can enhance the system capacity per given bandwidth substantially without sacrificing the expected bit error rate (BER) performance.
Adikari ABB, Fernando WAC, Weerakkody WARJ, Arachchi HK (2006) A Sequential Motion Compensation Refinement Technique for Distributed video coding of Wyner-Ziv frames, Proceedings International Conference on Image Processing, Vols 1-7 pp. 597-600 IEEE
Martinez JL, Kalva H, Fernandez-Escribano G, Fernando WAC, Cuenca P (2009) WYNER-ZIV TO H.264 VIDEO TRANSCODER, 2009 16TH IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING, VOLS 1-6 pp. 2905-2908 IEEE
This paper proposes an improved Wyner-Ziv to H.264 video transcoder as part of a framework for mobile to mobile video communications. In this scheme, the user devices keep the low complexity constraints by using the Wyner-Ziv encoding and H.264 decoding algorithms. They shift their complexities to the network where the proposed transcoder is allocated. The main goal of the transcoder is to convert the bitstream and reduce the delay efficiently. The results show that the proposed transcoder reduces the complexity by a factor of 95% with a negligible rate-distortion loss.
Danish E, De Silva V, Fernando A, De Alwis C, Kondoz A (2014) Content Aware Resource Allocation in OFDM Systems For Energy Efficient Video Transmission, 2014 IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS (ICCE) pp. 458-459 IEEE
Rajakaruna RMTP, Fernando WAC, ?ali? J (2012) Lagrange-based video encoder optimisation to enhance motion representation in the compressed-domain, Proceedings - IEEE International Conference on Multimedia and Expo pp. 479-484
Compressed-domain content analysis enables fast content-based video applications. However, conventional encoder implementation, limited to optimising data compression, does not necessarily result in content representative compressed features. In this paper, we present a novel method for video encoder optimisation that enhances reliability of content representation in the compressed video. We propose a configurable encoder model to jointly optimise bit-rate, distortion and content representation of the encoded video. In encoder optimisation for motion estimation, we analyse the behaviour of motion representation and compression efficiency over a range of content complexities. A mathematical model to control the extent of noise in selected motion vectors is presented. We demonstrate that the compressed domain motion information can be enhanced without incurring a rate-distortion overhead. The computational overheads are marginal and can be eliminated by exploiting the inherently parallel nature of the proposed optimisation model. © 2012 IEEE.
Badem MB, Fernando WAC, Kondoz AM (2010) Transform domain distributed video coding with spatial correlations, MULTIMEDIA TOOLS AND APPLICATIONS 48 (3) pp. 369-379 SPRINGER
Weerakkody WARJ, Fernando WAC, Badem MB, Kondoz AM (2009) Nonlinear quantisation for pixel domain distributed video coding, ELECTRONICS LETTERS 45 (5) pp. 261-U36 INST ENGINEERING TECHNOLOGY-IET
De Alwis C, Kodikara Arachchi H, Fernando A, Kondoz AK (2013) Towards minimising the coefficient vector overhead in random linear network coding,
Kamolrat B, Fernando WAC, Mrak M, Kondoz A (2008) Joint source and channel coding for 3D video with depth image - Based rendering, IEEE T CONSUM ELECTR 54 (2) pp. 887-894 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Shi Z, Fernando WAC, Kondoz A (2012) An efficient fast motion estimation in H.264/AVC by exploiting motion correlation character, CSAE 2012 - Proceedings, 2012 IEEE International Conference on Computer Science and Automation Engineering 3 pp. 298-302
The new video coding standard, H.264/AVC, has achieved significant compression gain by utilizing several advanced techniques. Motion estimation (ME) is one of the most important elements to reduce the motion residual. However it results in heavy computational burden. In this paper, a novel fast ME search algorithm, which exposits the correlation character between predicted and optimal motion vectors (MVs), is presented for H.264/AVC. According to motion vector prediction, search window is adaptively divided into several regions with calculation of its motion correlation probability. Specifically, it combines MVs' direction correlation and locality correlation. A novel Priority Region List, which indicates search process and selects the number of search points, is dynamically updated. The simulation results show that the proposed algorithm reduces 23% of motion estimation encoding time and 60% of average search points while maintaining the same RD performance compared with that of UMHexagonS algorithm, which is adopted in H.264 reference software. © 2012 IEEE.
Thanapirom S, Fernando WAC, Edirisinghe EA (2005) Zerotree-based stereoscopic video CODEC, OPTICAL ENGINEERING 44 (7) ARTN 077004 SPIE-INT SOCIETY OPTICAL ENGINEERING
Shahriari A, Fernando WAC, Arachchi HK (2006) Adaptive error concealment with radial basis neuro-fuzzy networks for video communication over lossy channels, 2006 International Conference on Industrial and Information Systems, Vols 1 and 2 pp. 600-604 IEEE
Yasakethu SLP, Fernando WAC, Kamolrat B, Kondoz A (2009) Analyzing Perceptual Attributes of 3D Video, IEEE T CONSUM ELECTR 55 (2) pp. 864-872 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
The 3D (3 Dimensional) video technologies are emerging to provide more immersive media content compared to conventional 2D (2Dimensional) video applications. In this paper we propose a joint source channel coding scheme (JSCC) for colour and depth based 3D video coding using subjective quality of 3D video. We considered different source and channel coding rates to find the optimum JSCC scheme under a given channel bit rate for a WiMAX based communication channel. More often 3D video quality is measured using rigorous and time-consuming subjective evaluation test campaigns. Hence this paper further extends the above study to investigate the relationship between perceptual attributes of 3D video and overall 3D quality and the correlation of these perceptual attributes with several objective quality measures for 3D video content. The results show that, Gaussian and linear polynomial mathematical models can be used to approximate the relationship between depth perception and image quality with overall 3D quality. Also results implies that, VQM and SSIM quality measures of individual left and right views can be effectively used in predicting the image quality and depth perception of 3D video respectively.
Mallikarachchi T, Fernando A, Arachchi HK (2014) Effective coding unit size decision based on motion homogeneity classification for HEVC inter prediction, 2014 IEEE International Conference on Image Processing, ICIP 2014 pp. 3691-3695
© 2014 IEEE. Determining the best partitioning structure for a given Coding Tree Unit (CTU) is one of the most time consuming operations within the HEVC encoder. The brute force search through quad tree hierarchy has a significant impact on the encoding time especially on high definition (HD) videos. This paper presents a fast coding unit size decision-taking algorithm for inter prediction in HEVC. The proposed algorithm uses a motion homogeneity based classification approach utilizing RD cost as a feature vector. Simulation results show that the proposed algorithm achieves an average of 73.25% encoding time efficiency improvement with similar rate distortion performance compared to HEVC HM12.0 reference software.
Mallikarachchi T, Fernando A, Arachchi HK (2015) Fast Coding Unit Size Selection for HEVC Inter Prediction, 2015 IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS (ICCE) pp. 457-458 IEEE
Malekmohamadi H, Fernando WAC, Kondoz AM (2012) A new reduced reference objective quality metric for stereoscopic video, 2012 IEEE Globecom Workshops, GC Wkshps 2012 pp. 1325-1328
A new reduced reference (RR) objective quality metric for stereoscopic video is proposed that incorporates spatial neighbouring information. The contrast measures from grey level co-occurrence matrices (GLCM) for both colour and depth are the main parts of spatial information. Side information are extracted from edge information of original video and sent through an auxiliary channel. The other important factor in the proposed metric is the unequal weight of colour and depth views, which can maximise the performance of the proposed metric for some specific values. Performance of the proposed metric is validated through series of subjective tests to show how it correlates subjective quality scores. The average correlation of the proposed metric and subjective quality scores is 0.82 when colour to depth importance ratio is near 4. © 2012 IEEE.
Adikari A, Fernando WAC, Arachchic HK (2006) Context based motion and disparity vector prediction algorithm for H.264 based stereoscopic video coding, IEICE ELECTRONICS EXPRESS 3 (13) pp. 299-303 IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG
Chatterjee S, Fernando WAC (2004) Blind estimation of channel and modulation scheme in adaptive modulation schemes for OFDM-CDMA based 4G systems, IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 50 (4) pp. 1065-1075 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Yasakethu SLP, Weerakkody WARJ, Fernando WAC, Pereira F, Kondoz AM (2009) An Improved Decoding Algorithm for DVC Over Multipath Error Prone Wireless Channels, IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 19 (10) pp. 1543-1548 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Fernando WAC (2010) Guest editorial: Special issue on distributed video coding, Multimedia Tools and Applications 48 (3) pp. 367-368
Alreshoodi M, Danish E, Woods J, Fernando A, De Alwis C (2015) Prediction of Perceptual Quality for Mobile 3D Video Using Fuzzy Inference Systems, 2015 IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS (ICCE) pp. 130-131 IEEE
Perera R, Fernando A, Mallikarachchi T, Arachchi HK, Pourazad M (2014) QoE aware resource allocation for video communications over LTE based mobile networks, Proceedings of the 2014 10th International Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness, QSHINE 2014 pp. 63-69
© 2014 ICST.As the limits of video compression and usable wireless radio resources are exhausted, providing increased protection to critical data is regarded as a way forward to increase the effective capacity for delivering video data. This paper explores the provisioning of selective protection in the physical layer to critical video data and evaluates its effectiveness when transmitted through a wireless multipath fading channel. In this paper, the transmission of HEVC encoded video through an LTE-A wireless channel is considered. HEVC encoded video data is ranked based on how often each area of the picture is referenced by subsequent frames within a GOP in the sequence. The critical video data is allotted to the most robust OFDM resource blocks (RBs), which are the radio resources in the time-frequency domain of the LTE-A physical layer, to provide superior protection. The RBs are ranked based on a prediction for their robustness against noise. Simulation results show that the proposed content aware resource allocation scheme helps to improve the objective video quality up to 37dB at lower channel SNR levels when compared against the reference system, which treats video data uniformly. Alternatively, with the proposed technique the transmitted signal power can be lowered by 30% without sacrificing video quality at the receiver.
De Silva DVSX, Fernando WAC, Worrall ST, Yasakethu SLP, Kondoz AM (2010) Just noticeable difference in depth model for stereoscopic 3D displays, Multimedia and Expo (ICME), 2010 IEEE International Conference on pp. 1219 -1224-1219 -1224
Adikari B, Fernando A, Weerakkody R, Kondoz AM (2009) An Iterative Fusion Technique for Dynamic Side Information Refinement in Pixel Domain Distributed Video Coding, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES E92A (6) pp. 1417-1423 IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG
Vu HG, Rajatheva RMAP, Fernando WAC (2003) Performance of iterative multiuser receiver for turbo-coded DS-CDMA, 57TH IEEE VEHICULAR TECHNOLOGY CONFERENCE, VTC 2003-SPRING, VOLS 1-4, PROCEEDINGS pp. 1610-1613 IEEE
Thantulage G, Kalganova T, Fernando WAC (2006) A grid-based ant colony algorithm for automatic 3D hose routing, 2006 IEEE CONGRESS ON EVOLUTIONARY COMPUTATION, VOLS 1-6 pp. 48-55 IEEE
Danish E, Fernando A, Abdul-Hameed O, Pourazad M (2014) Perceptual Quality-Driven Resource Allocation in Energy-Aware Wireless Video Multicasting, 2014 10TH INTERNATIONAL CONFERENCE ON HETEROGENEOUS NETWORKING FOR QUALITY, RELIABILITY, SECURITY AND ROBUSTNESS (QSHINE) pp. 101-107 IEEE
Weerakkody WARJ, Fernando WAC, Martinez JL, Cuenca P, Quiles F (2007) An iterative refinement technique for side information generation in DVC, 2007 IEEE INTERNATIONAL CONFERENCE ON MULTIMEDIA AND EXPO, VOLS 1-5 pp. 164-167 IEEE
Shi Z, Fernando WAC, Kondoz A (2011) Adaptive direction search algorithms based on motion correlation for block motion estimation, IEEE Transactions on Consumer Electronics 57 (3) pp. 1354-1361
The new video coding standard, H.264/AVC, has achieved significant compression gain by utilizing several advanced techniques. Block-Matching Motion Estimation is one of the most important elements to reduce the motion residual. However, it results in heavy computational burden and limits the application for real-time video service. In this paper, a fast motion estimation algorithm called Simulated Annealing Adaptive Search (SAAS) is proposed to reduce the computational load. The basic idea of the proposed scheme is based on adjusting search pattern not only for each frame, but also for each block. Initially, the adaptive search pattern is performed by statistical analysis of previous frame's Motion Vector Correlation. Then the search pattern is adjusted for each block according to Predicted Motion Vector. According to motion vector correlation statistics information, search region is adaptively divided and Simulated Annealing (SA) mechanism is adopted to select search power for each region and to avoid trapping into local minima. Experimental results indicate that the proposed algorithm offers considerable improvement in computing time and motion search points at the same rate-distortion performance, compared to the conventional fast motion estimation algorithm. © 2006 IEEE.
Adikari ABB, Fernando WAC, Arachchi HK, Weerakkody WARJ (2006) Low complex key frame encoding with high quality Wyner-Ziv coding, 2006 International Conference on Industrial and Information Systems, Vols 1 and 2 pp. 605-609 IEEE
Adedoyin S, Fernando WAC, Aggoun A, Weerakkody WARJ (2007) An ES based effecient motion estimation technique for 3D integral video compression, 2007 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING, VOLS 1-7 pp. 1521-1524 IEEE
Fernando WAC (2010) Special issue on distributed video coding, MULTIMEDIA TOOLS AND APPLICATIONS 48 (3) pp. 367-368 SPRINGER
Adikari ABB, Fernando WAC, Arachchi HK, Loo KK (2005) A H.264 compliant stereoscopic video CODEC, Canadian Conference on Electrical and Computer Engineering 2005 pp. 1622-1625
Due to the provision of a more natural representation of a scene in the form of left and right eye views, a stereoscopic imaging system provides a more effective method for image/video display. Unfortunately the vast amount of information that needs to be transmitted/stored to represent a stereo image pair / video sequence, has so far hindered its use in commercial applications. However, by properly exploiting the spatial, temporal and binocular redundancy, a stereo image pair or a sequence could be compressed and transmitted through a single monocular channel's bandwidth without unduly sacrificing the perceived stereoscopic image quality. In this paper, we present a new technique for coding stereo video sequences based on H.264 [1] video codec. The proposed codec exploits disparity and worldline correlation in addition to the advance compression techniques inherited by the H.264 standard to achieve a higher video quality especially in the low bit rates. We compare the performance of the proposed CODEC with a DCT-based, modified MPEG-2 stereo video CODEC [2] and ZTE based stereo video CODEC [3]. We show that the proposed CODEC outperforms the benchmark CODECs in coding both main and auxiliary streams by up to 9.0 dB PSNR gain. © 2005 IEEE.
Fernando WAC, Rajatheva RMAP (2001) Suitability of turbo coded OFDM for LEO satellite channels in global mobile communications, ICCE: 2001 INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS, DIGEST OF TECHNICAL PAPERS pp. 196-197 IEEE
Danish E, Silva VD, Fernando A (2015) Application of genetic and greedy algorithms for power efficiency in adaptive sub-channel and bit allocation, Proceedings - 6th International Conference on Computational Intelligence, Communication Systems and Networks, CICSyN 2014 pp. 192-195
© 2014 IEEE.Energy consumption has attracted significant attention by the research community in response to the green initiatives pertaining to electronic equipment and devices. This is especially applicable to wireless environments since the trend of adopting wireless technologies is on the increase. Hence, in this paper we suggest a method for wireless communications to minimize the total power required for transmission. The method considers sub-channel and bit allocation in orthogonal frequency division multiplexing systems for a multiuser scenario. The problem is addressed by exploiting genetic and greedy algorithms mutually to attain minimum power allocation among several users. Through simulation, the proposed method is shown to outperform static allocation methods with an average of 37.20% less required power. It is also shown that the more required bitrate by users the more power saving is achieved.
De Alwis C, Kodikara Arachchi H, Fernando A, Kondoz A (2013) Network Coding For Error Resilient Transmission of Stereoscopic 3D Video,
Shi Z, Fernando WAC, Kondoz AM (2013) Fast inter mode decision using residual homogeneity in H.264/AVC, ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings pp. 1384-1388
The H.264/AVC coding standard has achieved significant coding gain by using flexible block sizes inter prediction. However, the complexity of inter-mode decision is extremely high. In this paper, a fast inter-mode decision algorithm is presented by exploiting residual homogeneity for both macroblock and sub-macroblock levels. In this algorithm, the residual homogeneity indicators calculated in three directions are used to identify the block's homogeneous characteristic. Normalized motion vector activity is also considered to improve the performance. The experimental results illustrate that the proposed algorithm achieves about 49% of computational complexity saving in terms of encoding time, while with negligible quality degradation, compared to H.264/AVC reference software JM. © 2013 IEEE.
Sigdel S, Ahmed KM, Fernando A (2003) Performance of multicarrier-CDMA uplink with antenna arrays and multiuser detection, JOURNAL OF COMMUNICATIONS AND NETWORKS 5 (2) pp. 150-156 KOREAN INST COMMUNICATIONS SCIENCES (K I C S)
De Alwis C, Arachchi HK, Fernando A, Pourazad M (2014) Content and network-aware multicast over wireless networks, Proceedings of the 2014 10th International Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness, QSHINE 2014 pp. 122-128
© 2014 ICST.This paper proposes content and network-aware redundancy allocation algorithms for channel coding and network coding to optimally deliver data and video multicast services over error prone wireless mesh networks. Each network node allocates redundancies for channel coding and network coding taking in to account the content properties, channel bandwidth and channel status to improve the end-to-end performance of data and video multicast applications. For data multicast applications, redundancies are allocated at each network node in such a way that the total amount of redundant bits transmitted is minimised. As for video multicast applications, redundancies are allocated considering the priority of video packets such that the probability of delivering high priority video packets is increased. This not only ensures the continuous playback of a video but also increases the received video quality. Simulation results for bandwidth sensitive data multicast applications exhibit up to 10× reduction of the required amount of redundant bits compared to reference schemes to achieve a 100% packet delivery ratio. Similarly, for delay sensitive video multicast applications, simulation results exhibit up to 3.5dB PSNR gains in the received video quality.
De Silva DVSX, Fernando WAC (2009) Intra Mode Selection for Depth Map Coding to Minimize Rendering Distortions in 3D Video, IEEE T CONSUM ELECTR 55 (4) pp. 2385-2393 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Depth image Based Rendering (DIBR) is a technique that generates virtual views for multiview video applications from 3D video represented in color plus depth format. The depth map is not viewed by end users. However, it helps to generate different views as required by the application. Therefore, the depth maps need to be compressed in a way that it minimizes distortions in the rendered views. By doing so, it would be possible to generate high quality virtual views, using compressed depth maps. This paper presents two mode selection techniques based on genetic algorithms for encoding depth maps. In the proposed techniques, the encoding modes are decided so that the distortion in the rendered view, v is, minimized. Simulation results illustrate that proposed techniques improve the objective quality of the rendered virtual views by up to 2 dB over the Lagrange Optimization based mode selection technique that considers the distortions only in the depth map.
Dissanayake MB, De Silva DVSX, Worrall ST, Fernando WAC (2010) Error resilience technique for multi-view coding using redundant disparity vectors, Multimedia and Expo (ICME), 2010 IEEE International Conference on pp. 1712 -1717-1712 -1717
Mayuran S, Fernando WAC, Kalganova T, Arachchi HK (2007) Evolutionary strategy based improved motion estimation technique for H.264 video coding, 2006 Canadian Conference on Electrical and Computer Engineering, Vols 1-5 pp. 1488-1491 IEEE
Rajakaruna RMTP, Fernando WAC, Calic J (2011) Application-aware video coding architecture using camera and object motion-models, 2011 6th International Conference on Industrial and Information Systems, ICIIS 2011 - Conference Proceedings pp. 76-81
The proliferation of video consumption, especially over mobile devices, has created a demand for efficient interactive video applications and high-level video analysis. This is particularly significant in real-time applications and resource-limited scenarios. Pixel-domain video processing is often inefficient for many of these applications due to its complexity, whereas compressed domain processing offer fast but unreliable results. In order to achieve fast and effective video processing, this paper proposes a novel video encoding architecture that facilitate efficient compressed domain processing, while maintaining compliance with the mainstream coding standards. This is achieved by optimizing the accuracy of motion information embedded in the compressed video, in addition to compression efficiency. In a motion detection application, we demonstrate that the motion estimated by the proposed encoder can be directly used to extract object information, as opposed to conventionally coded video. The incurred rate distortion overheads can be weighed against the reduced processing required for video analysis targeting a wide spectrum of computer vision applications. © 2011 IEEE.
Dissanayake MB, Hewage CTER, Worrall ST, Fernando WAC, Kondoz AM (2008) REDUNDANT MOTION VECTORS FOR IMPROVED ERROR RESILIENCE IN H.264/AVC CODED VIDEO, 2008 IEEE INTERNATIONAL CONFERENCE ON MULTIMEDIA AND EXPO, VOLS 1-4 pp. 25-28 IEEE
Kamolrat B, Fernando WAC, Mrak M, Kondoz A (2009) 3D Motion Estimation for Depth Image Coding in 3D Video Coding, IEEE T CONSUM ELECTR 55 (2) pp. 824-830 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
In this paper, a new solution is introduced for the efficient compression of 3D video based on color and depth maps. While standard video codecs are designed for coding monoscopic videos, their application to depth maps is found to be suboptimal. With regard to the special properties of the depth maps, we propose an extension to conventional video coding in order to take advantage of object motion ill the depth direction. Instead of performing a 2D motion search, as is common in conventional video codecs, we propose the use of a 3D motion search that is able to better exploit the temporal correlations of 3D content. In this new framework, the motion of blocks it? depth maps are described using 3D motion vectors (x, y, z), representing the horizontal, vertical, and depth directions respectively. This leads to more accurate motion prediction and a smaller residual. The experimental results show that the proposed technique delivers an improvement in motion compensation, which leads to gains in compression efficiency.
Martinez JL, Weerakkody WARJ, Fernando WAC, Quiles F, Kondoz AM (2008) Turbo trellis coded modulation for transform domain distributed video coding, ELECTRONICS LETTERS 44 (15) pp. 899-901 INST ENGINEERING TECHNOLOGY-IET
Danish E, Fernando A, Abdul-Hameed O, Alshamrani M, Kondoz A (2014) Perceptual QoE based resource allocation for mobile 3D video communications, Digest of Technical Papers - IEEE International Conference on Consumer Electronics pp. 454-455
This paper suggests a power and bandwidth efficient resource allocation approach for mobile networks based on consumer's perception of 3D video. We simulate a mobile 3D video transmission through which we identify the correlation between receiver's signal-to-noise ratio and perceived quality. Our QoE-based approach is shown to save up to 33.13% in power and grant up to 50% more data bits for transmission, compared to QoS-based techniques. © 2014 IEEE.
Fernando WAC, Canagarajah CN, Bull DR (2000) Wipe production in MPEG-2 compressed video, 2000 INTERNATIONAL CONFERENCE ON IMAGE PROCESSING, VOL II, PROCEEDINGS pp. 303-306 IEEE
Yasakethu SLP, Femando WAC, Kondoz AM (2009) Rate Controlling in Off Line 3D Video Coding Using Evolution Strategy, IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 55 (1) pp. 150-157
Fernando WAC, Canagarajah CN, Bull DR (2000) Video special effects editing in MPEG-2 compressed video, ISCAS 2000: IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS - PROCEEDINGS, VOL II pp. 281-284 IEEE
Shi Z, Fernando WAC, De Silva DVSX (2010) A motion estimation algorithm based on Predictive Intensive Direction Search for H.264/AVC, Multimedia and Expo (ICME), 2010 IEEE International Conference on pp. 667 -672-667 -672
De Silva DVSX, Fernando WAC, Kodikaraarachchi H, Worrall ST, Kondoz AM (2010) Adaptive sharpening of depth maps for 3D-TV, ELECTRONICS LETTERS 46 (23) pp. 1546-1547 INST ENGINEERING TECHNOLOGY-IET
Fernando WAC (2006) Sudden scene change detection in compressed video using interpolated macroblocks in B-frames, MULTIMEDIA TOOLS AND APPLICATIONS 28 (3) pp. 301-320 SPRINGER
Ruangsuthinarupap S, Ahmed KM, Fernando WAC, Khan MER (2004) PAPR reduction by combining selected mapping and selected spreading code in MC-CDMA systems, ISCC2004: NINTH INTERNATIONAL SYMPOSIUM ON COMPUTERS AND COMMUNICATIONS, VOLS 1 AND 2, PROCEEDINGS pp. 725-729 IEEE
Arachchi HK, Fernando WAC (2005) PSO based bit rate optimization for MPEG-1/2 video coding., ICIP (2) 2 pp. 329-332 IEEE
One of the significant problems in video compression schemes is the high fluctuation in output data rate over the video sequence. These compression schemes, in general, utilize a rate control algorithm in order to maintain the output data rate at a constant level regardless of the properties of the video sequence and differences in compression ratios of different picture types. In this paper, we propose a novel rate control algorithm with the Particle Swarm Optimization (PSO) [1] technique for offline MPEG-1/2 codecs. We model the rate control problem as an optimization problem and use the PSO to obtain a better optimal solution. Experimental results show that the proposed method can improve the average picture signal to noise ratio (PSNR) by more than 2 dB. © 2005 IEEE.
Wasantha MK, Fernando WAC (2002) QAM based adaptive modulation for OFDM-CDMA wireless networks, 5TH INTERNATIONAL SYMPOSIUM ON WIRELESS PERSONAL MULTIMEDIA COMMUNICATIONS, VOLS 1-3, PROCEEDINGS pp. 715-719 IEEE
Tun M, Fernando WAC (2006) An error-resilient algorithm based on partitioning of the wavelet transform coefficients for a DIRAC video codec, Information Visualization pp. 615-620 IEEE COMPUTER SOC
Adedoyin S, Fernando WAC, Aggoun A (2007) A JOINT MOTION AND DISPARITY BASED ESTIMATION TECHNIQUE WITH HALF PIXEL REFINEMENT FOR 3D INTEGRAL VIDEO COMPRESSION, ICSPC: 2007 IEEE INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATIONS, VOLS 1-3, PROCEEDINGS pp. 348-351 IEEE
Adedoyin S, Fernando WAC, Aggoun A (2007) An adaptable ES based motion estimation technique for 3D integral video compression, ICIIS 2007 - 2nd International Conference on Industrial and Information Systems 2007, Conference Proceedings pp. 383-386
In this paper we propose an efficient approach to use an adaptable ES algorithm to compress motion information of 3D integral video sequences. The integral video sequence is decomposed into 8 viewpoint video sequences and a block search is performed to exploit the motion estimation redundancies between neighboring blocks to maximize the compression. An Adaptable Evolutionary Strategy (ES) based search algorithm is used to reduce the coding complexity. Experimental results show that the ES based strategy can reduce the motion estimation complexity by 90%. ©2007 IEEE.
Adedoyin S, Fernando WAC, Kondoz AM (2010) Scalable MDC for 3D stereoscopic video using motion vector encoding, 2010 IEEE International Conference on Multimedia and Expo, ICME 2010 pp. 1718-1723
Interest in 3D video visualization systems is a ever growing field. Such areas include the provision of 3D content to users thus opening the exploration of 3D video communication and transmission. To address communication and transmission one must consider error resilience. Multiple Description Coding (MDC) can provide a robust video communication over wireless networks. However it can introduce high levels of redundancy. In this paper, we propose a scalable MDC architecture using motion vector (MV) encoding for 3D video. Experimental results show that the proposed algorithm can improve the frame quality by up to 2dB over a pixel based interpolation scheme with residual coding while significantly reducing the bit rate compared to a pixel and motion interpolation schemes. © 2010 IEEE.
Sivartantharasa P, Fernando WAC, Arachchi HK (2006) Region of Interest video coding with flexible macroblock ordering, 2006 International Conference on Industrial and Information Systems, Vols 1 and 2 pp. 596-599 IEEE
Martínez-Rach MO, De Silva D, Fernando A, Arachchi HK, Granado OL, Malumbres M (2012) A low complexity wavelet based depth map encoder for low bit rate 3D video applications, Digest of Technical Papers - IEEE International Conference on Consumer Electronics pp. 235-236
Depth maps, which aid the virtual view generation process in Depth Image Based Rendering (DIBR) applications in 3D video, are generally piecewise smooth images with sharp depth discontinuities. Compression artifacts that occur along the depth discontinuities often lead to poor quality of generated virtual views. In line with the importance of depth discontinuities towards view generation, we propose a non-uniform quantization method for wavelet based encoding of depth maps. Average rendering quality improvements of up to 0.8dB could be achieved. © 2012 IEEE.
Yasakethu SLP, Fernando WAC, Adedoyin S, Kondoz A (2009) A Rate Control Technique for H.264/AVC Using Subjective Quality of 2D/3D Video, 2009 IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS pp. 451-452 IEEE
De Alwis C, Kodikara Arachchi H, De Silva V, Fernando A, Kondoz A (2012) Robust video communication using Random Linear Network Coding with Pre-Coding and Interleaving, IEEE PES Innovative Smart Grid Technologies Conference Europe pp. 2269-2272
With the increasing popularity of online video streaming and broadcasting applications, video transmission has become the most bandwidth consumed application in the Internet. Unless resource utilisation is further optimised, existing networks would not be able to accommodate the forecasted demand for high volume video traffic. Random Linear Network Coding (RLNC) is a promising approach to increase the network throughput and robustness in order to facilitate high volume traffic. However, the performance gain obtained using RLNC decreases when the network packet loss rate increases. In response, this paper proposes to incorporate RLNC with a combined interleaving and a coding technique to improve the effectiveness of generating redundant packet combinations over classical RLNC to enhance the robustness against packet losses. Simulation results illustrate that the proposed method improves the probability of recovering lost data over the classical RLNC and the video transmission simulation results exhibit up to 5dB increase in PSNR and up to 14% increase in VQM utilising the same network resources at the same network conditions. © 2012 IEEE.
Shi Z, Fernando WAC, Kondoz AM (2012) A hybrid coded block patterns based fast mode decision in H.264/AVC, Proceedings of the 2012 IEEE International Conference on Multimedia and Expo Workshops, ICMEW 2012 pp. 13-18
The video coding standard H.264/AVC although possesses the advantage of higher coding efficiency compared to previous ones, it would result in a high computational complexity due to various block sizes motion estimation for multi-modes decision. In this paper, a hybrid inter-mode decision algorithm is presented, combining coded block pattern (CBP) with motion activity and Rate-Distortion (RD) cost. In this algorithm, CBP and CBP 4x4, which indicate none-zero coefficient block, is used to determine candidate modes at macro block level and sub-macro block level. Further, the normalized motion activity is used to identify the homogeneity of the block and target the candidate modes set more accurate. An early termination is also made between macro block level and sub-macro block level by RD cost comparing. The experimental results show that the proposed algorithm achieves approximately 60% of computational complexity saving in terms of encoding time, while with negligible quality degradation, compared to the conventional method in H.264/AVC. © 2012 IEEE.
De Alwis C, Arachchi HK, Fernando A, De Silva V, Danish E, Kondoz A (2014) On the multicast of delay sensitive data in erasure networks using practical network coding, Digest of Technical Papers - IEEE International Conference on Consumer Electronics pp. 470-471
We present a method to estimate the probability of decoding a network coded packet generation transmitted across an erasure network. Simulation results closely correlate to estimated results. The proposed method is used to multicast delay sensitive data at the a.) required delivery probability b.) optimal throughput. © 2014 IEEE.
De Silva V, Kodikara Arachchi H, Ekmekcioglu E, Fernando A, Dogan S, Kondoz A, Savas S (2012) Psycho-physical Limits of Interocular Blur Suppression and its Application to Asymmetric Stereoscopic Video Delivery, 19th IEEE International Packet Video Workshop pp. 184-189 IEEE
It is well known that when the two eyes are provided with two views of different resolutions the overall perception is dominated by the high resolution view. This property, known as binocular suppression, is effectively used to reduce the bit rate required for stereoscopic video delivery, where one view of the stereo pair is encoded at a much lower quality than the other. There have been significant amount of effort in the recent past to measure the just noticeable level of asymmetry between the two views, where asymmetry is achieved by encoding views at two quantization levels. However, encoding artifacts introduce both blurring and blocking artifacts in to the stereo views, which are perceived differently by the human visual system. Therefore, in this paper, we design a set of psycho-physical experiments to measure the just noticeable level of asymmetric blur at various spatial frequencies, luminance contrasts and orientations. The subjective results suggest that humans could tolerate a significant amount of asymmetry introduced by blur, and the level of tolerance is independent of the spatial frequency or luminance contrast. Furthermore, the results of this paper illustrate that when asymmetry is introduced by unequal quantization, the just noticeable level of asymmetry is driven by the blocking artifacts. In general, stereoscopic asymmetry introduced by way of asymmetric blurring is preferred over asymmetric compression. It is expected that the subjective results of this paper will have important use cases in objective measurement of stereoscopic video quality and asymmetric compression and processing of stereoscopic video.
Martinez JL, Fernandez-Escribano G, Kalva H, Weerakkody WARJ, Fernando WAC, Garrido A (2008) FEEDBACK FREE DVC ARCHITECTURE USING MACHINE LEARNING, 2008 15TH IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING, VOLS 1-5 pp. 1140-1143 IEEE
Yasakethu L, Adedoyin S, Fernando A, Kondoz AM (2009) Rate controlling in H.264/AVC using subjective quality of video and evolution strategy, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences E92-A (3) pp. 808-815
In this paper, we propose a rate control technique for H.264/AVC using subjective quality of video for off line video coding. We propose to use Video Quality Metric (VQM) with an evolution strategy algorithm, which is capable of identifying the best possible quantization parameters for each frame/macroblock to encode the video sequence such that it would maximize the subjective quality of the entire video sequence subjected to the target bit rate. Simulation results suggest that the proposed technique can improve the RD performance of the H.264/AVC codec significantly. With the proposed technique, up to 40% bit rate reduction can be achieved at the same video quality. Furthermore, results show that the proposed technique can improve the subjective quality of the encoded video significantly for video sequences especially with high motion. Copyright © 2009 The Institute of Electronics, Information and Communication Engineers.
Kocharoen P, Ahmed KM, Rajatheva RMAP, Fernando WAC (2006) Mesh-based video coding for low bit-rate communications, IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 52 (2) pp. 611-620 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Martinez JL, Weerakkody WARJ, Fernando WAC, Fernandez-Escribano G, Kalva H, Garrido A (2009) Distributed Video Coding using Turbo Trellis Coded Modulation, VISUAL COMPUTER 25 (1) pp. 69-82 SPRINGER
Perera R, Fernando A, Mallikarachchi T, Arachchi HK, Pourazad M (2014) QoE Aware Resource Allocation for Video Communications over LTE Based Mobile Networks, 2014 10TH INTERNATIONAL CONFERENCE ON HETEROGENEOUS NETWORKING FOR QUALITY, RELIABILITY, SECURITY AND ROBUSTNESS (QSHINE) pp. 63-69 IEEE
Nur, G, De Silva, v, Kodikara Arachchi, H, Kondoz, A, Fernando, W, Martinez-Rach, M O, Dogan S (2012) Sensitivity of the HVS for Binocular Disparity Cue in 3D Displays under Different Ambient Illumination Conditions,
Fernando WAC, Canagarajah CN, Bull DR (1999) DFD based scene segmentation for H.263 video sequences, ISCAS '99: PROCEEDINGS OF THE 1999 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOL 4 pp. 520-523 IEEE
Dao ND, Fernando WAC (2003) Channel coding for H.264 video in constant bit rate transmission context over 3G mobile systems, PROCEEDINGS OF THE 2003 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOL II pp. 896-899 IEEE
Thanapirom S, Fernando WAC, Edirisinghe EA (2003) A Zerotree stereo video encoder, PROCEEDINGS OF THE 2003 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOL II pp. 608-611 IEEE
Foomooljareon P, Fernando WAC (2002) Input sequence envelope scaling in PAPR reduction of OFDM, 5TH INTERNATIONAL SYMPOSIUM ON WIRELESS PERSONAL MULTIMEDIA COMMUNICATIONS, VOLS 1-3, PROCEEDINGS pp. 140-144 IEEE
Weerakkody WARJ, Fernando WAC, Kondoz AM (2008) An enhanced reconstruction algorithm for unidirectional distributed video coding, 2008 IEEE INTERNATIONAL SYMPOSIUM ON CONSUMER ELECTRONICS, VOLS 1 AND 2 pp. 47-50 IEEE
Adedoyin S, Fernando WAC, Kodikara Arachchi H, Kalganova T, Loo KK (2005) An evolutionary strategy based motion estimation algorithm for H.264 video codecs, Canadian Conference on Electrical and Computer Engineering 2005 pp. 927-930
In this paper, we propose a new motion estimation algorithm based on evolutionary strategy (ES) for the H.264 video codec applied to monoscopic video. The proposed technique applies in macroblock basis and performs a parallel local search for the motion vector associated with the minimum motion compensated residue. For this purpose (¼+»)-ES is used with heuristically and randomly generated population of initial motion vectors. Experimental results show that the proposed scheme can reduce the computational complexity up to 50% of the motion estimation algorithm used in the H.264 reference codec at the same picture quality. Therefore, the proposed algorithm provides a significant improvement in motion estimation in the H.264 video codec. © 2005 IEEE.
Adikari B, Fernando WAC, Kodikara Arachchi H (2006) A new motion and disparity vector prediction technique for H.264 based stereoscopic video coding, Proceedings - IEEE International Symposium on Circuits and Systems pp. 927-930
Owing to the provision of a more natural and realistic reconstruction of a scene in the form of two views presented to the left and right eyes, stereoscopic imaging/video technology offers a more attractive and effective solution for imaging/video production. However due to the fact that more information has to be transmitted to reproduce the stereoscopic image pair, the transmission bit rate might be considerably increased if the available redundancies are not properly exploited. This paper presents a novel motion and disparity vector prediction technique for the H.264 based stereoscopic video codec that can be used for future consumer video applications such as 3D TV and 3D mobile communication in order to generate the real 3D perception in the human psycho-visual system. The proposed technique predicts both motion and disparity vectors more intelligently using the previously coded motion and disparity vectors of the surrounding macroblocks. Results show that the proposed algorithm can reduce the average bit budget by about 12% compared to the conventional motion and disparity prediction algorithm employed by the H.264 [1] based stereoscopic codec[2]. Furthermore, results suggest that the objective quality of the sequences is also improved. © 2006 IEEE.
Arachchi HK, Fernando WAC (2003) Improving the video quality at scene transitions for MPEG-1/2 video encoders, Proceedings - IEEE International Symposium on Circuits and Systems 2
The objective of rate control in video coding is to utilize the available communication bandwidth to transmit the highest quality video. This paper presents an innovative rate control algorithm for MPEG-1/2 encoders to improve the video quality at sudden and gradual scene transitions. The algorithm works in three steps. The fixed encoding structure of the MPEG data stream is disturbed by forcing an extension or termination of the last GOP of the first scene such that the first anchor picture of the second scene becomes an I-coded picture. P-pictures are provided with additional bits to compensate for the inefficient forward prediction during gradual scene transitions. The complexity parameters of each picture type are corrected with an iterative algorithm, Experimental results show that with the proposed algorithm, both objective and subjective quality of MPEG video can be improved significantly during scene transitions.
Kocharoen P, Ahmed KM, Rajatheva RMAP, Fernando WAC (2005) Adaptive mesh generation for mesh-based image coding using node elimination approach, ICC 2005: IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS, VOLS 1-5 pp. 2052-2056 IEEE
Weerakkody WARJ, Fernando WAC, Adikari ABB (2006) Distributed video coding of Wyner-Ziv frames using trellis coded modulation, 2006 Canadian Conference on Electrical and Computer Engineering, Vols 1-5 pp. 1612-1615 IEEE
Joveluro P, Malekmohamadi H, Fernando WAC, Kondoz AM (2010) Perceptual Video Quality Metric for 3D video quality assessment, 3DTV-Conference: The True Vision - Capture, Transmission and Display of 3D Video (3DTV-CON), 2010 pp. 1-4
One method of evaluating the quality of stereoscopic video is the use of conventional two dimensional (2D) objective metrics. Metrics with good representation of the Human Visual System (HVS) will present more accurate evaluation. In this paper we propose a perceptual based objective metric for 2D videos for 3D video quality evaluation. The proposed Perceptual Quality Metric (PQM) shows better results for 3D video quality evaluation and outperforms the Video Quality Metric (VQM); as it is sensitive to slight changes in image degradation and error quantification starts at pixel level right up to the sequence level. Verifications are done through series of subjective tests to show the level of correlation of PQM and user scores.
Malekmohamadi H, Fernando WAC, Danish E, Kondoz AM (2014) Subjective quality estimation based on neural networks for stereoscopic videos, Digest of Technical Papers - IEEE International Conference on Consumer Electronics pp. 107-108
A neural network based technique is proposed to estimate subjective quality of stereoscopic videos. Moreover, to utilize this model for applications where availability of reference signal is not possible to receiver, it applies objective quality of video with minimum dependency on reference signal. This paper presents fast, accurate and consistent subjective quality estimation. Feasibility and accuracy of the proposed technique is thoroughly analyzed with extensive subjective experiments and simulations. Results illustrate that performance measure of 92.3% in subjective quality estimation can be achieved with the proposed technique. © 2014 IEEE.
Sinha A, Fernando WAC (2007) Analysing and realising wireless mesh networks as a replacement for lon based distributed control networks for clean room environment, 2007 CANADIAN CONFERENCE ON ELECTRICAL AND COMPUTER ENGINEERING, VOLS 1-3 pp. 357-359 IEEE
Adikari ABB, Fernando WAC, Weerakkody WARJ (2007) Iterative Wyner-Ziv decoding for unidirectional distributed video coding, ELECTRONICS LETTERS 43 (2) pp. 93-95 INST ENGINEERING TECHNOLOGY-IET
Weerakkody R, Fernando A, Kondoz AM (2009) Modifying the Turbo Decoder for DVC over Wireless Channels, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES E92A (8) pp. 2009-2016 IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG
Arachchi HK, Fernando WAC, Panchadcharam S, Weerakkody WARJ (2007) Unequal error protection technique for ROI based H.264 video coding, 2006 Canadian Conference on Electrical and Computer Engineering, Vols 1-5 pp. 1462-1465 IEEE
Adikari ABB, Fernando WAC, Weerakkody WARJ, Kondoz AM (2008) JOINT SPATIAL AND TEMPORAL CORRELATION EXPLOITATION FOR WYNER-ZIV FRAMES CODING IN DVC, 2008 IEEE INTERNATIONAL CONFERENCE ON MULTIMEDIA AND EXPO, VOLS 1-4 pp. 589-+ IEEE
Yasakethu SLP, Fernando WAC, Badem MB, Kondoz AM (2008) Quality Analysis of Side Information Refinement in Transform-Based DVC, 4th International Conference on Information and Automation for Sustainability pp. 148-153 IEEE
Distributed Video Coding (DVC) has been proposed for different new application domains. This rise is apparently motivated by the very attractive features of its flexibility for building very low cost video encoders and the very high built-in error resilience when applied over noisy communication channels. These features could be very effectively exploited in several application domains including wireless sensor networks for security surveillance and mobile video communications. So far DVC has used PSNR to measure the quality of the decoded video. In this paper, we analyze the performance of the DVC encoded video with three different quality matrices: PSNR, VQM and SSIM. We used one of our side information refinement algorithms in transform domain DVC as the basis for all comparisons. Simulation results show that the side information refinement technique based on motion analysis can achieve a significant coding gain with respective to all quality matrices considered. However, subjective results show that VQM has a very high correlation with the MOS which suggests that VQM is a better quality metric that can be used in DVC.
Yasakethu SLP, Worrall ST, De Silva DVSX, Fernando WAC, Kondoz AM (2011) A compound depth and image quality metric for measuring the effects of packet loss on 3D video, 17th DSP 2011 International Conference on Digital Signal Processing, Proceedings
Interest in 3D video has surged in recent years. However, efforts to improve the quality of compression and transmission schemes are severely hampered by a lack of effective quality evaluation metrics. This is a particularly severe problem for researchers trying to improve the robustness of video transmission to packet loss. Subjective tests for evaluating error robustness present huge requirements in terms of time and resources. To solve this problem, this paper presents a quality metric for 3D video, and evaluates its effectiveness for the measurement of quality in the presence of packet loss. A key feature of the work is the use of depth planes to enable the metric to better model how the Human Visual System (HVS) perceives 3D video. The quality metric results are compared with subjective test results. The correlation between the proposed quality metric and the subjective test results is shown to be stronger than standard quality metrics, such as Video Quality Metric (VQM). © 2011 IEEE.
Yasakethu SLP, Fernando WAC, Adedoyin S, Kondoz A (2008) A rate control technique for off line H.264/AVC video coding using subjective quality of video, IEEE T CONSUM ELECTR 54 (3) pp. 1465-1472 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
De Silva DVSX, Fernando WAC, Kodikara Arachchi H (2010) A new mode selection technique for coding depth maps of 3D video, Proceedings of IEEE International Conference on Acoustics, Speech and Signal Processing pp. 686-689
Compression of Depth maps that are used in 3D video systems based on Depth Image Based Rendering (DIBR) poses a new challenge in video coding, since it is not a sequence of images for final viewing by end users rather an aid for rendering. Therefore, compressing depth maps using existing video coding techniques yields unacceptable distortions while rendering virtual views. In this paper we propose a novel mode selection method for offline compression of depth maps by selecting modes collaboratively considering an entire row of macroblocks together. For selecting these modes while encoding, we propose a novel distortion criteria that incorporates rendering distortions instead of distortion of depth map itself. A genetic algorithm based optimization technique is used for the mode selection. The simulation results suggest that the proposed technique can improve the PSNR up to 1.6dB in the rendered stereoscopic views in comparison to the block wise mode selection method based on Lagrange Optimization and the distortion of the depth map itself.
Badem MB, Mrak M, Fernando WAC (2008) Side information refinement using motion estimation in DC domain for transform-based distributed video coding, ELECTRONICS LETTERS 44 (16) pp. 965-966 INST ENGINEERING TECHNOLOGY-IET
Fernando WAC, Canagarajah CN, Bull DR (2000) Fade, dissolve and wipe production in MPEG-2 compressed video, IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 46 (3) pp. 717-727 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Shahriari A, Fernando WAC, Arachchi HK (2006) Adaptive video concealment using neural networks for H.264 based video coding, 2006 Canadian Conference on Electrical and Computer Engineering, Vols 1-5 pp. 1500-1503 IEEE
Danish E, Fernando A, Abdul-Hameed O, Pourazad M (2014) Perceptual quality-driven resource allocation in energy-aware wireless video multicasting, Proceedings of the 2014 10th International Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness, QSHINE 2014 pp. 101-107
© 2014 ICST.In conjunction with the rising trend towards consumption of resource-hungry multimedia content over wireless medium, efficient radio resource allocation (eRRA) represents an ongoing challenge to network operators. This paper explores the application of multicasting in light of an eRRA that considers the perceptual quality aspect of wireless video transmission such that transmission energy is minimized. A multiuser orthogonal frequency-division multiplexing (OFDM) environment is considered. The resource allocation scheme presented is based on the genetic algorithm (GA) and offers fairness through the balance of average perceptual quality and minimal total energy among all subscribers in multicasting groups. In order to assist with this balance, a utility function is introduced as a fitness function for the GA. The allocation scheme relies on a well-established video quality model (VQM) for assessment of user-perceived quality. Simulation results show that the allocation scheme helps to preserve the energy requirement at low levels despite the proportionate rise in the number of subscribers. Moreover, perceived quality is well-secured and maintained at high levels, with a consistent increase of the utility value. Reflecting on today's consumption patterns of popular video content, adoption of the presented scheme in multicasting would help lessen the carbon footprint emitted by wireless communications, while consumers' quality of experience (QoE) is maintained.
De Silva DVSX, Fernando WAC, Nur G, Ekmekcioglu E, Worrall ST (2010) 3D video assessment with Just Noticeable Difference in Depth evaluation, Proceedings - International Conference on Image Processing, ICIP pp. 4013-4016
The ability to provide a realistic perception of depth is the core added functionality of modern 3D video display systems. At present, there is no standard method to assess the perception of depth in 3D video. Existence of such methods would immensely enhance the progression of 3D video research. This paper focuses on the depth perception assessment in color plus depth representation of 3D video. In this paper, we subjectively evaluate the depth perceived by the users on an auto stereoscopic display, and analyze its variation with the impairments introduced during the compression of the depth images. The variation of the subjective perception of depth is explained based on another evaluation that is carried out to identify the Just Noticeable Difference in Depth (JNDD) perceived by the subjects. The JNDD corresponds to the sensitivity of the observers to the changes in depth in a 3D video scene. Even though only the effects of compression artifacts are considered in this paper, the proposed assessment technique, based on the JNDD values can be used in any future depth perception assessment work. © 2010 IEEE.
Malekmohamadi H, Fernando WAC, Danish E, Kondoz AM (2014) Subjective Quality Estimation Based on Neural Networks for Stereoscopic Videos, 2014 IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS (ICCE) pp. 109-110 IEEE
Malekmohamadi H, Fernando WAC, Kondoz AM (2012) Content-based subjective quality prediction in stereoscopic videos with machine learning, Electronics Letters 48 (21) pp. 1344-1346
A model exploiting machine learning and content analysis is proposed to predict the subjective quality of stereoscopic videos. This model offers an automated, accurate and consistent subjective quality prediction. The feasibility and accuracy of the proposed technique has been thoroughly analysed with extensive subjective experiments and simulations. Results illustrate that a performance measure of 0.954 in subjective quality prediction can be achieved with the proposed technique. © 2012 The Institution of Engineering and Technology.
Kamolrat B, Fernando WAC, Mrak M, Kondoz A (2008) FLEXIBLE MOTION MODEL WITH VARIABLE SIZE BLOCKS FOR DEPTH FRAMES CODING IN COLOUR-DEPTH BASED 3D VIDEO CODING, 2008 IEEE INTERNATIONAL CONFERENCE ON MULTIMEDIA AND EXPO, VOLS 1-4 pp. 573-576 IEEE
Badem MB, Weerakkody R, Fernando A, Kondoz AM (2009) Design of a non-linear quantizer for transform domain DVC, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences E92-A (3) pp. 847-852
Distributed Video Coding (DVC) is an emerging video coding paradigm that is characterized by a flexible architecture for designing very low cost video encoders. This feature could be very effectively utilized in a number of potential many-to-one type video coding applications. However, the compression efficiency of the latest DVC implementations still falls behind the state-of-the-art in conventional video coding technologies, namely H.264/AVC. In this paper, a novel non-linear quantization algorithm is proposed for DVC in order to improve the rate-distortion (RD) performance. The proposed solution is expected to exploit the dominant contribution to the picture quality from the relatively small coefficients when the high concentration of the coefficients near zero as evident when the residual input video signal for the Wyner-Ziv frames is considered in the transform domain. The performance of the proposed solution incorporating the non-linear quantizer is compared with the performance of an existing transform domain DVC solution that uses a linear quantizer. The simulation results show a consistently improved RD performance at all bitrates when different test video sequences with varying motion levels are considered. Copyright © 2009 The Institute of Electronics, Information and Communication Engineers.
Adikari ABB, Fernando WAC, Weerakkody WARJ (2007) Independent key frame coding using correlated pixels in distributed video coding, ELECTRONICS LETTERS 43 (7) pp. 387-388 INSTITUTION ENGINEERING TECHNOLOGY-IET
Thanapirom S, Fernando WAC, Edirisinghe EA (2003) A zerotree stereo video encoder, Proceedings - IEEE International Symposium on Circuits and Systems 2
Over the past decade, the growing interests in realistic visual communication systems have lead to the rapid development of 3D visual compression techniques. A stereoscopic system is one way of stimulating 3D perception. Without exploiting the high redundancy in a stereo pair, the amount of data required to store or transmit it is doubled, when compared to the same in monocular images. In this paper, we present a new technique for coding stereo video sequences based on Discrete Wavelet Transform (DWT). The proposed technique exploits Zerotree Entropy Coding (ZTE) that makes use of the wavelet block concept to achieve low bit rate stereo video coding. One of the two image streams, namely the main stream, is independently coded by a modified Zerotree video coder and the second stream, namely the auxiliary stream, is predicted based on disparity compensation. The residual image of auxiliary stream is then coded by a modified Zerotree video coder. Results show that the proposed encoder can achieve 50% bandwidth reduction compared to the ZTE based monoscopic compression encoder.
Malekmohamadi H, Fernando WAC, Kondoz AM (2012) Automatic QOE prediction in stereoscopic videos, Proceedings of the 2012 IEEE International Conference on Multimedia and Expo Workshops, ICMEW 2012 pp. 581-586
In this paper, we propose a method for automatic quality of experience (QoE) prediction in stereoscopic videos. QoE, though embodying the subjective measures of the end user's perceived quality, can be expressed in relation to some quality of service (QoS) parameters. Having information on content types in modelling QoE-QoS interactions is advantageous as videos with the same QoS parameters may have different subjective scores due to different content types. Consequently, using content clustering with the help of spatio-temporal activities within depth layers, QoE predictor is designed per each content cluster utilising full reference (FR) and no reference (NR) metrics. Finally, the performance of the proposed QoE prediction algorithm is evaluated extensively and the overall measure of success value equal to 95.4% is achieved for the test sequences. This model can be applied for QoE control in video provisioning systems. © 2012 IEEE.
Chatterjee S, Fernando WAC, Ahmed KM (2003) CPM schemes for adaptive modulation based coded MC-CDMA systems, IEEE TENCON 2003: CONFERENCE ON CONVERGENT TECHNOLOGIES FOR THE ASIA-PACIFIC REGION, VOLS 1-4 pp. 142-145 IEEE
Adedoyin S, Fernando WAC, Aggoun A, Kondoz KM (2007) Motion and disparity estimation with self adapted evolutionary strategy in 3D video coding, IEEE Transactions on Consumer Electronics 53 (4) pp. 1768-1775
Real world information, obtained by humans is three dimensional (3-D). In experimental user-trials, subjective assessments have clearly demonstrated the increased impact of 3-D pictures compared to conventional flat-picture techniques. It is reasonable, therefore, that we humans want an imaging system that produces pictures that are as natural and real as things we see and experience every day. Three-dimensional imaging and hence, 3-D television (3DTV) are very promising approaches expected to satisfy these desires. Integral imaging, which can capture true 3D color images with only one camera, has been seen as the right technology to offer stress-free viewing to audiences of more than one person. In this paper, we propose a novel approach to use Evolutionary Strategy (ES) for joint motion and disparity estimation to compress 3D integral video sequences. We propose to decompose the integral video sequence down to viewpoint video sequences and jointly exploit motion and disparity redundancies to maximize the compression using a self adapted ES. A half pixel refinement algorithm is then applied by interpolating macro blocks in the previous frame to further improve the video quality. Experimental results demonstrate that the proposed adaptable ES with Half Pixel Joint Motion and Disparity Estimation can up to 1.5 dB objective quality gain without any additional computational cost over our previous algorithm.1Furthermore, the proposed technique get similar objective quality compared to the full search algorithm by reducing the computational cost up to 90%. © 2007 IEEE.
Danish E, Fernando A, Abdul-Hameed O, Alshamrani M, Kondoz A (2014) Perceptual QoE Based Resource Allocation For Mobile 3D Video Communications, 2014 IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS (ICCE) pp. 456-457 IEEE
Kamolrat B, Fernando WAC, Mrak M (2008) Rate controlling for color and depth based 3D video coding, Proceedings of SPIE - The International Society for Optical Engineering 7073
Rate control is a very important tool for any kind of video coding and transmission. Even though there are many rate control techniques designed for 2D video, not much work has been carried out in this area for 3D video. In this paper, a novel rate control approach for 3D video based on color and depth maps is introduced. The aim of this rate control algorithm is to keep the 3D video quality near constant. Since the 3D video is synthesized from color and depth maps and the final quality of 3D video is more influenced by color sequence rather than depth maps, the qualities of both color and depth maps are firstly varied until the target 3D quality is achieved with minimal bit rate. Subsequently, the PSNR of both color and depth maps at the optimum point are maintained for the entire group of picture (GOP). The bit-allocation problem is solved by introducing a Lagrangian optimization cost function. According to experimental results, the proposed rate control technique is capable to adjust the bit rate allocated to the color and depth maps sequences adaptively in order to maximize 3D video quality which is measured by PSNR of the synthesized left and right views using reconstructed color and depth map sequences.
Weerakkody WARJ, Fernando WAC, Muraleetharan K, Adedoyin S (2007) Distributed Video Coding With MIMO for Video Wireless Communications, ICSPC: 2007 IEEE INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATIONS, VOLS 1-3, PROCEEDINGS pp. 384-387 IEEE
Nguyen HH, Fernando WAC (2007) Optimum linear decoding of vector quantisation transmitted over a CDMA channel, IET COMMUNICATIONS 1 (6) pp. 1206-1211 INST ENGINEERING TECHNOLOGY-IET
Fernando WAC, Loo KK (2004) Abrupt and gradual scene transition detection in MPEG-4 compressed video sequences using texture and macroblock information, ICIP: 2004 INTERNATIONAL CONFERENCE ON IMAGE PROCESSING, VOLS 1- 5 pp. 1589-1592 IEEE
Fernando WAC, Canagarajah CN, Bull DR (1998) Video segmentation and classification for content based storage and retrieval using motion vectors, STORAGE AND RETRIEVAL FOR IMAGE AND VIDEO DATABASES VII 3656 pp. 687-698 SPIE-INT SOC OPTICAL ENGINEERING
Shi ZR, Fernando WAC, De Silva DVSX (2010) A MOTION ESTIMATION ALGORITHM BASED ON PREDICTIVE INTENSIVE DIRECTION SEARCH FOR H.264/AVC, 2010 IEEE INTERNATIONAL CONFERENCE ON MULTIMEDIA AND EXPO (ICME 2010) pp. 667-672 IEEE
Motion estimation is the most computationally intensive element in a block based video codec. In this paper, a novel Predictive Intensive Direction Searching (PIDS) algorithm is proposed to reduce the computational load of H.264/AVC video codec. Based on the direction of predicted motion vector, the search area is adaptively divided into one region of intensive-direction-searching and several regions of coarse-direction-searching. Then the extended hexagon search is used to refine the final optimal motion vector. The experimental results indicate that the proposed algorithm achieves a reduction of 15% motion estimation time, while incurring only 0.5% increment on the bite rate compared with that of UMHexagonS algorithm, which is adopted by the H.264/AVC reference software.
Kulupana G, Talagala DS, Kodikara Arachchi H, Fernando WAC (2015) Optimized Resource Distribution for Interactive TV Applications, IEEE Transactions on Consumer Electronics pp. 70-71
Though ubiquitous, the full potential of consumer electronic devices in the home, as content creators, remains underutilized due to the limited interaction between the consumers and the existing on-demand application and media services. Although services such as interactive television could change this, the geographic distribution of groups of consumers and the need for on-the-fly media processing that this entails, makes the efficient utilization of resources a complex optimization task requiring mechanisms to simultaneously allocate processing and network resources to groups of users. However, these technologies have not yet been developed, and brute force methods remain prohibitively complex. In order to overcome this problem, this paper proposes heuristic algorithms to both generate end-to-end delay bound multicast trees for individual groups of users and to co-locate multiple multicast trees, such that a minimum group quality metric can be satisfied. The performance of the proposed heuristic solution is evaluated in terms of the serving probability, i.e., the resource utilization efficiency, and computation time of the resource allocation decision making process. Simulation results show that improvements in the serving probability of up to 50%, in comparison with existing generic resource allocation schemes, and several orders of magnitude reduction of the computation time, in comparison to an optimal linear programming solution approach, can be achieved.
Arachchi HK, Fernando WAC (2003) Improving the video quality at scene transitions for MPEG-1/2 video encoders, PROCEEDINGS OF THE 2003 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOL II pp. 852-855 IEEE
Fernando WAC, Rajatheva RMAP (1998) Performance of turbo and trellis coded OFDM for LEO satellite channels in global mobile communications, ICC 98 - 1998 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS VOLS 1-3 pp. 412-416 IEEE
Marti nez JL, Weerakkody WARJ, Cuenca P, Quiles F, Fernando WAC (2008) Transform domain Wyner-Ziv codec based on turbo trellis codes modulation, Lecture Notes in Computer Science: Advances in Multimedia Modelling 4903 pp. 413-424
In recent years, with emerging applications such as wireless video surveillance, multimedia sensor networks, disposable video cameras, medical applications and mobile camera phones, the traditional video coding architecture is being challenged. For these emerging applications, Distributed Video Coding (DVC) seems to be able to offer efficient and low-complexity encoding video compression. In this paper, we present a novel transform domain distributed video coding algorithm based on Turbo Trellis Coded Modulation (TTCM). As in the conventional turbo based Wyner-Ziv encoder, transform quantized coefficients are applied to the TTCM encoder and parity bits are generated from both constituent encoders. However, TTCM symbols are not generated at the encoder since they are not sent to the decoder. Parity bits produced by the TTCM encoder are stored in a buffer and transmitted to the decoder upon request. TTCM symbols are generated at the decoder and these symbols are passed to the TTCM decoder for demodulation. Experimental results show that significant rate-distortion (RD) gains compared to the state-of-the-art results available in the literature can be obtained.
Yasakethu SLP, De Silva DVSX, Fernando WAC, Kondoz A (2010) Predicting sensation of depth in 3D video, ELECTRONICS LETTERS 46 (12) pp. 837-838 INST ENGINEERING TECHNOLOGY-IET
Martfnez JL, Fernando WAC, Weerakkody WARJ, Oliver J, Lopez O, Martinez M, Perez M, Cuenca P, Quiles F (2007) Low-complexity TTCM based distributed video coding architecture, ADVANCES IN IMAGE AND VIDEO TECHNOLOGY, PROCEEDINGS 4872 pp. 841-852 SPRINGER-VERLAG BERLIN
Kulupana G, Talagala DS, Kodikara Arachchi H, Fernando WAC (2016) Error Resilience Aware Motion Estimation and Mode Selection for HEVC Video Transmission, ICCE International Conference On Consumer Electronics 2016
Error concealment techniques such as motion copying require significant changes to HEVC (High Efficiency Video Coding) motion estimation process when incorporated in error resilience frameworks. This paper demonstrates a novel motion estimation mechanism incorporating the concealment impact from future coding frames to achieve an average 0.73 dB gain over the state-of-the-art.
Mallikarachchi T, Talagala D, Kodikara Arachchi H, Fernando W (2016) Content-Adaptive Feature-Based CU Size Prediction for Fast Low-Delay Video Encoding in HEVC, IEEE Transactions on Circuits and Systems for Video Technology 28 (3) pp. 693-705 IEEE
Determining the best partitioning structure of a Coding Tree Unit (CTU) is one of the most time consuming operations in HEVC encoding. Specifically, it is the evaluation of the quadtree hierarchy using the Rate-Distortion (RD) optimization that has the most significant impact on the encoding time, especially in the cases of High Definition (HD) and Ultra High Definition (UHD) videos. In order to expedite the encoding for low delay applications, this paper proposes a Coding Unit (CU) size selection and encoding algorithm for inter-prediction in the HEVC. To this end, it describes (i) two CU classification models based on Inter N N mode motion features and RD cost thresholds to predict the CU split decision, (ii) an online training scheme for dynamic content adaptation, (iii) a motion vector reuse mechanism to expedite the motion estimation process, and finally introduces (iv) a computational complexity to coding efficiency trade-off process to enable flexible control of the algorithm. The experimental results reveal that the proposed algorithm achieves a consistent average encoding time performance ranging from 55% ? 58% and 57% ? 61% with average Bjøntegaard Delta Bit Rate (BDBR) increases of 1.93% ? 2.26% and 2.14% ? 2.33% compared to the HEVC 16.0 reference software for the low delay P and low delay B configurations, respectively, across a wide range of content types and bit rates.
Kulupana G, Talagala DS, Arachchi H, Fernando WAC (2017) QoS, Energy and Cost Efficient Resource Allocation for Cloud-Based Interactive TV Applications, IEIE Transactions on Smart Processing and Computing 6 (3) pp. 158-167 Institute of Electronics and Information Engineers
Internet-based social and interactive video applications have become major constituents of the envisaged applications for next-generation multimedia networks. However, inherently dynamic network conditions, together with varying user expectations, pose many challenges for resource allocation mechanisms for such applications. Yet, in addition to addressing these challenges, service providers must also consider how to mitigate their operational costs (e.g., energy costs, equipment costs) while satisfying the end-user quality of service (QoS) expectations. This paper proposes a heuristic solution to the problem, where the energy incurred by the applications, and the monetary costs associated with the service infrastructure, are minimized while simultaneously maximizing the average end-user QoS. We evaluate the performance of the proposed solution in terms of serving probability, i.e., the likelihood of being able to allocate resources to groups of users, the computation time of the resource allocation process, and the adaptability and sensitivity to dynamic network conditions. The proposed method demonstrates improvements in serving probability of up to 27%, in comparison with greedy resource allocation schemes, and a several-orders-of-magnitude reduction in computation time, compared to the linear programming approach, which significantly reduces the service-interrupted user percentage when operating under variable network conditions.
Rajakaruna R, Fernando WAC, Calic J (2011) Video encoder optimization for efficient video analysis in resource-limited systems, IEEE 6th International Conference on Industrial and Information Systems pp. 175-180 IEEE
Performance of real-time video processing applications such as surveillance systems, content-based search, is limited by the complexity of video content analysis in the pixel domain. A low complex alternative is to analyse the video in the compressed domain, where content features already available in the compressed video are directly used in the analysis. However, this is achieved at the expense of output precision and reliability, due to compression-efficiency driven feature selection at the encoder. Therefore, video applications could benefit from enhanced reliability of data embedded in the compressed video. In this paper, we present a scalable optimization model that addresses the accuracy of content features in parallel with the conventional rate-distortion optimization criterion. We analyse and optimize rate-distortion performance of video encoder under content description accuracy constrain, using a motion calibrated synthetic data set containing a range of scene and motion complexity levels. Finally, using a natural video data set, we demonstrate that the proposed optimization framework can be used to enhance compressed feature accuracy without incurring a rate-distortion overhead.
The continuous challenge of capturing and representing the high ?delity representation of the real-world scene on display devices to invoke true-to-life visual sensations has been the driving force behind the development of High Dynamic Range (HDR) imaging technologies. HDR imaging technologies enables the capture, storage and display of the light levels and colours inherent in the original capture of content. By doing so, it enables the HDR video to provide the sensation and quality which is closer to the seamless and immersive real-world appearance. However, existing conventional display devices being Low Dynamic Range (LDR) in nature and multimedia delivery technologies being designed and optimized for the 8-bit LDR video signal, does not support HDR video visualization and distribution, respectively. In this thesis, we explore how to exploit and utilize the existing multimedia delivery technologies for HDR video distribution keeping in view the need for backward-compatibility with already existing LDR displays.

Unlike LDR video, HDR video utilizes higher bit-depth to faithfully preserve the luminance dynamic range encountered in the real-world scene and thus, cannot be distributed through current 8-bit video distribution infrastructure. Further, although HDR information can be utilized for rendering a closer to real-world LDR representation, this cannot be done by the LDR video player and display devices due to the incompatibility with HDR video. These challenges are addressed in our ?rst contribution. We propose a two-layer scalable HDR video distribution method which is backward-compatible with the existing encoders and with ubiquitous LDR display devices. The base layer in the proposed method carries the LDR representation for LDR displays, generated from the HDR video. Whereas, the extension layer encodes the HDR information as a 8-bit video signal. An e?cient mapping function is employed in the extension layer to improve the coding e?ciency of the extension layer which in turn improves the HDR video quality in comparison to the other backward-compatible HDR video distribution methods.

A review and performance evaluation of the state-of-the-art HDR video distribution methods is presented in our second contribution. This was done to categorize and critique the existing HDR video distribution methods in order to contribute to ongoing HDR video distribution standardization e?orts which are presently impeded by the lack of comprehensive performance evaluation. 5 HDR video distribution methods, including ones in contention for being standardized as HDR video distribution method, were evaluated to present the performance assessment and behaviour of these methods for HDR video sequences having di?erent characteristics. We showed that the performance of HDR video distribution methods is generally a?ected by the dynamic range and spatio-temporal characteristics of the HDR videos. Further, apart from identifying the most suitable distribution method for HDR video, we also highlighted the discrepancy in the prediction of HDR quality measured through the di?erent HDR quality metrics employed.

In our last contribution, we ?rst presented the novel usage of the Perceptual Transfer Function (PTF) for improving and optimizing the compression performance of the state-of-the-art video compression standard; High E?ciency Video Coding (HEVC), for the HDR video compression. The PTF is utilized in the Rate-Distortion Optimization (RDO) process and results in an improved coding performance in terms of the Rate-Distortion e?ciency for HDR video compression. We showed that using a PTF which is backward-compatible with the LDR transfer function can improve the HEVC compression e?ciency which implies that HEVC needs to be optimized for the HDR video compression. Based on these observation, we further optimized the HEVC RateControl (RC) algorithm for the HDR video compression. A new »-QP relationship is proposed which better estimates the relat

HEVC (High Efficiency Video Coding), the latest and most popular video coding standard, has succeeded in significantly improving performance in terms of the compression efficiency by exploiting more and more spatial and temporal dependencies. Consequently, HEVC coded videos are much more susceptible to network impairments, which unless mitigated by some means, can have a significant detrimental impact on the end user?s perceived Quality of Experience (QoE).
Furthermore, emerging HEVC based interactive video applications pose many challenges which cannot be resolved using traditional resource allocation algorithms or error resilience schemes. These include dynamic network conditions, the need for maintaining the QoE across a group of interacting users, strict delay constraints, as well as the geographic and temporal variations in the interactive content processing requirements, all of which must collectively determine and adapt the appropriate video coding parameters and network level resource allocation to enhance the overall QoE.
To this end, this research proposes application layer and network layer methodologies to improve the end user QoE. First, an end user's video quality prediction model is proposed for HEVC based video communications under error prone channels. The model which incorporates the errors in the motion vectors, the reference pixels and the pixel clipping operations during the modelling phase, has subsequently demonstrated only a 3% prediction error whereas the state-of-the-art methods couldn't reach below 17.5% under identical conditions. Later, these distortion values are re-used inside the HEVC Rate-Distortion Optimization (RDO) process to realize a 20%-40% improvement in the BD-rate compared to the state-of-the-art error resilient schemes.
Secondly, a novel motion vector estimation algorithm is proposed to select motion vectors which unlike the existing methods not only mitigate the error propagation from the previous frames but also improve the concealment accuracy of the future encoding frames. The proposed algorithm has consequently demonstrated 1.48 dB PSNR gain compared to the existing methods for the same bit rate.
Finally a joint network and computational resource allocation scheme and an optimal transmission route selection algorithm is proposed to maximize the end user QoE of an interactive video application.
The results demonstrates that the proposed resource allocation scheme can outperform the existing methods by a 50% margin in the serving probabilities and several orders of magnitude reduction in the computational times.
Mallikarachchi Thanuja, Talagala Dumidu S., Arachchi Hemantha Kodikara, Fernando Anil (2018) Decoding-Complexity-Aware HEVC Encoding Using a Complexity-Rate-Distortion Model, IEEE Transactions on Consumer Electronics 64 (1) pp. 35-43 Institute of Electrical and Electronics Engineers (IEEE)
The energy consumption of Consumer Electronic (CE) devices during media playback is inexorably linked to the computational complexity of decoding compressed video. Reducing a CE device?s the energy consumption is therefore becoming ever more challenging with the increasing video resolutions and the complexity of the video coding algorithms. To this end, this paper proposes a framework that alters the video bit stream to reduce the decoding complexity and simultaneously limits the impact on the coding efficiency. In this context, this paper (i) first performs an analysis to determine the trade-off between the decoding complexity, video quality and bit rate with respect to a reference decoder implementation on a General Purpose Processor (GPP) architecture. Thereafter, (ii) a novel generic decoding complexity-aware video coding algorithm is proposed to generate decoding complexity-rate-distortion optimized High Efficiency Video Coding (HEVC) bit streams. The experimental results reveal that the bit streams generated by the proposed algorithm achieve 29.43% and 13.22% decoding complexity reductions for a similar video quality with minimal coding efficiency impact compared to the state-of-the-art approaches when applied to the HM16.0 and openHEVC decoder implementations, respectively. In addition, analysis of the energy consumption behavior for the same scenarios reveal up to 20% energy consumption reductions while achieving a similar video quality to that of HM 16.0 encoded HEVC bit streams.
Alreshoodi Mohammed, Danish Emad, Woods John, Fernando Anil, De Alwis Chamitha (2015) Prediction of Perceptual Quality for Mobile Video Using Fuzzy Inference Systems, IEEE Transactions on Consumer Electronics 61 (4) pp. 546-554 IEEE
Along with the rapid growth in consumer adoption of modern portable devices, video streaming is expected to dominate a large share of the global internet traffic in the near future. In the wireless communications domain, this trend creates considerable challenges to consumers? quality of experience (QoE). From a consumer-focused vision, predicting perceptual video quality is extremely important for QoE-based service provisioning. However, available QoE measurement techniques that adopt a full reference model are impractical in real-time transmission since they require the original video sequence to be available at the receiver?s end. Therefore, the primary aim of this study is to present a cross-layer no-reference prediction model for the perceptual quality of 3D video in the wireless domain. The contributions of this study are twofold: first, the impact of selected quality of service (QoS) parameters from both encoding and network levels on QoE is investigated. Also, the obtained QoS/QoE correlation is backed by thorough statistical analysis. Second, a prediction model based on fuzzy logic inference systems (FIS) is developed by mapping chosen QoS parameters to the measured QoE. This model enables a non-intrusive prediction of 3D visual quality. Conclusive results show a significantly high correlation between the predicted video quality and the objectively measured mean opinion scores (MOS). Objective MOS is also validated through methodical subjective assessments. For consumer?s QoE, this study advances the development of reference-free video quality prediction models and QoE control methods for 3D video streaming.
Kulupana Gosala, Talagala Dumidu S, Arachchi Hemantha Kodikara, Fernando Anil End User Video Quality Prediction and Coding
Parameters Selection at the Encoder for Robust
HEVC Video Transmission,
IEEE Transactions on Circuits and Systems for Video Technology IEEE
Abstract?Along with the rapid increase in the availability for high quality video formats such as HD (High Definition), UHD (Ultra HD) and HDR (High Dynamic Range), a huge demand for data rates during their transmission has become inevitable.
Consequently, the role of video compression techniques has become crucially important in the process of mitigating the data rate requirements. Even though the latest video codec HEVC (High Efficiency Video Coding) has succeeded in significantly reducing the data rate compared to its immediate predecessor H.264/AVC (Advanced Video Coding), the HEVC coded videos in the meantime have become even more vulnerable to network impairments. Therefore, it is equally important to assess the
consumers? perceived quality degradation prior to transmitting HEVC coded videos over an error prone network, and to include error resilient features so as to minimize the adverse effects those impairments. To this end, this paper proposes a probabilistic model which accurately predicts the overall distortion of the
decoded video at the encoder followed by an accurate QP-»
relationship which can be used in the RDO (Rate Distortion Optimization) process. During the derivation process of the
probabilistic model, the impacts from the motion vectors, the pixels in the reference frames and the clipping operations are accounted and consequently the model is capable of minimizing the prediction error as low as 3.11% whereas the state-of-theart methods can?t reach below 20.08% under identical conditions.
Furthermore, the enhanced RDO process has resulted in 21.41%-
43.59% improvement in the BD-rate compared to the state-ofthe-art error resilient algorithms.
Rakngan Sarat, Mallikarachchi Thanuja, Fernando Anil (2019) An adaptive video streaming framework for Scalable HEVC (SHVC) standard, Proceedings of the 2019 IEEE International Conference on Consumer Electronics (ICCE) pp. 1-2 Institute of Electrical and Electronics Engineers (IEEE)
This paper presents an implementation of a Media Aware Network Element (MANE) for dynamic video content adaptation in Scalable HEVC (SHVC) video streaming. The experimental results discuss the varying quality-to-playback time ratio and decoding power consumption with random access period in SHVC encoding under fluctuating and persistent network bandwidth conditions.
Erabadda Buddhiprabha, Mallikarachchi Thanuja, Kulupana Gosala, Fernando Anil (2018) Machine Learning Approaches for Intra-Prediction in HEVC, Proceedings of the 2018 IEEE 7th Global Conference on Consumer Electronics (GCCE) pp. 206-209 Institute of Electrical and Electronics Engineers (IEEE)
The use of machine learning techniques for encoding complexity reduction in recent video coding standards such as High Efficiency Video Coding (HEVC) has received prominent attention in the recent past. Yet, the dynamically changing nature of the video contents makes it evermore challenging to use rigid traditional inference models for predicting the encoding decisions for a given content. In this context, this paper investigates the resulting implications on the coding efficiency and the encoding complexity, when using offline trained and online trained machine-learning models for coding unit size selection in the HEVC intra-prediction. The experimental results demonstrate that the ground truth encoding statistics of the content being encoded, is crucial to the efficient encoding decision prediction when using machine learning based prediction models.
Kulupana Gosala, Talagala Dumidu, Fernando Anil, Arachchi Hemantha Kodikara (2018) Bit allocation and encoding parameter selection for rate-controlled error resilient HEVC video encoding, Proceedings of the 2018 IEEE International Conference on Consumer Electronics (ICCE) pp. 1-4 Institute of Electrical and Electronics Engineers (IEEE)
Even though the latest video compression techniques such as High Efficiency Video coding (HEVC) have succeeded in significantly alleviating the bandwidth consumption during high resolution video transmission, they have become severely susceptible to transmission errors. Overcoming the resulting temporal impact of the transmission errors on the decoded video requires efficient error resilient schemes that can introduce robustness features to the coded video in order to mitigate the negative impact on the viewer. To this end, this paper proposes a rate-controlled error resilient bit allocation scheme, together with an encoding parameter selection process, to adaptively determine the most robust video coding parameters and the decoder error concealment operations during the encoding itself. Consequently, the proposed method has demonstrated 0.48dB-0.62dB PSNR gain over the state-of-the art methods at the same bit rate.
Erabadda Buddhiprabha, Mallikarachchi Thanuja, Kulupana Gosala, Fernando Anil (2019) Content Adaptive Fast CU Size Selection for HEVC Intra-Prediction, Proceedings of the 2019 IEEE International Conference on Consumer Electronics (ICCE) pp. 1-2 Institute of Electrical and Electronics Engineers (IEEE)
This paper proposes a content adaptive fast CU size selection algorithm for HEVC intra-prediction using weighted support vector machines. The proposed algorithm demonstrates an average encoding time reduction of 52.38% with 1.19% average BDBR increase compared to HM16.1 reference encoder.
Udora Carl C., Mir Junaid, Galkandage Chatura, Fernando Anil (2019) QoE Modelling of High Dynamic Range Video, Proceedings of the 2019 IEEE International Conference on Consumer Electronics (ICCE) pp. 1-2 Institute of Electrical and Electronics Engineers (IEEE)
The level of user satisfaction has no standard way of measuring for HDR video content due to the proven difficulty of building HDR quality assessment metrics. To overcome this limitation, Quality of Experience (QoE) modelling of HDR video has been proposed to find a robust and accurate HDR video QoE metric. The proposed model is the first attempt towards assessing and devising a non-reference quality metric for HDR video. It is based on finding the correlation between the HDR video features and the subjective test results. The proposed model achieves a significant correlation score of 0.724 with the subjective results.