2008 Ieee International Conference on Multimedia and Expo, May 26, 2008
In [1], Adaptive Prediction Error Coding (APEC) in spatial and frequency domain is proposed and s... more In [1], Adaptive Prediction Error Coding (APEC) in spatial and frequency domain is proposed and significantly improves the coding efficiency of video coders. However, this approach comes with the expense of increased encoding complexity because of the need to perform Rate Distortion Optimization (RDO) for each block, to decide whether the block is coded in spatial or frequency domain. In this work, we propose novel fast mode decision algorithm operating on macroblock and block level to reduce the encoding complexity of APEC. The proposed algorithm estimates the edge orientation of the residual block using spatial domain filtering, and based on the estimated edge orientation, reduces the number of candidates to be checked in RDO. Furthermore, proposed method includes an early termination step that stops searching the best candidate based on the difference between spatial and frequency domain coding. Experimental results show that the proposed fast mode decision algorithm can achieve averagely 90.7% encoding time reduction of APEC with only about 0.06 dB loss in coding efficiency.
2009 Ieee International Conference on Acoustics Speech and Signal Processing, 2009
In our previous work, we introduced Spatially Varying Transforms (SVT) for video coding, where th... more In our previous work, we introduced Spatially Varying Transforms (SVT) for video coding, where the location of the transform block within the macroblock is not fixed but varying. In this paper, we extend this concept and present a novel method, called Variable Block-size Spatially Varying Transforms (VBSVT). VBSVT utilizes Variable Block-size Transforms (VBT) in the SVT framework, and is shown to be more preferable for coding prediction error with different characteristics than fixed block-size SVT and also the standard methods that use fixed or adaptive block sizes at fixed spatial locations. In addition, VBSVT has similar decoding complexity with fixed block-size SVT and lower decoding complexity compared to standard methods as only a portion of the prediction error needs to be decoded. Experimental results show that, VBSVT achieves 4.1% gain over H.264/AVC on average over a wide range of test set. Gains become more significant at high quality levels and go up to 13.5%, which makes the proposed algorithm very suitable for future video coding solutions focusing on high fidelity applications.
2007 Ieee International Conference on Acoustics Speech and Signal Processing Icassp 07, Apr 15, 2007
In this work, a novel sub-pixel interpolation algorithm is proposed for video coders targeted tow... more In this work, a novel sub-pixel interpolation algorithm is proposed for video coders targeted towards high resolution and high fidelity use cases. Proposed scheme is based on adapting the interpolation filter's symmetry assumptions in a Rate-Distortion-Optimized fashion, taking into account the coding rate and the statistical properties of each image of the video sequence. Experimental results show that, using the proposed algorithm a gain of up-to 1.1 dB is achieved compared to non-adaptive sub-pixel interpolation of H.264/AVC. Compared to other state-of-the-art adaptive sub-pixel interpolation methods, a gain of up-to 0.5 dB is achieved. Proposed scheme outperforms H.264/AVC for all test cases; however, improvement is more significant at high bitrates and at high resolutions. This is especially important for future video coding solutions targeting high fidelity video applications.
2006 Ieee International Conference on Acoustics Speech and Signal Processing Proceedings, May 14, 2006
In this work, we propose novel encoder algorithms for the state-of-the-art video coding standard ... more In this work, we propose novel encoder algorithms for the state-of-the-art video coding standard H.264, to generate decoder friendly video bitstreams. Using the proposed algorithms, it is possible to generate bitstreams requiring significantly less decoding complexity, with negligible effect on picture quality. This is achieved by using novel algorithms for mode decision and motion estimation that bias easy-todecode motion vectors in a Rate-Distortion optimized fashion. Experimental results show that, more than 15% decoding complexity reduction is achieved with less than a 0.1 dB penalty on the average video quality. We believe that this approach has potential in various use cases especially in mobile multimedia systems, where the video decoder operation is often dominating the handsets power consumption.
Acoustics Speech and Signal Processing 1988 Icassp 88 1988 International Conference on, Mar 1, 2008
Technologies used in today's video coding standards have been designed and optimized mainly for S... more Technologies used in today's video coding standards have been designed and optimized mainly for Standard Definition (SD) resolutions and below. When moving to higher resolutions, data in video frames tend to become more correlated spatially. In this paper, we study how to take advantage of this phenomenon to lower computational requirements for High Definition (HD) video coding. A coding method based on low complexity pruned transforms and interleaving of multiple transform coefficient blocks is proposed. An example implementation of this method in the context of H.264/AVC is also presented. Experimental results show that the proposed method maintains the high compression efficiency of H.264/AVC while significantly lowering the coding complexity of the codec.
2014 Ieee International Conference on Image Processing, Oct 27, 2014
First version of the latest video coding standard, High Efficiency Video Coding (HEVC), only supp... more First version of the latest video coding standard, High Efficiency Video Coding (HEVC), only supports coding of video in YUV 4:2:0 chroma format. An extension of the standard that will support other chroma formats is currently under development, however, version 1 decoders will not be able to handle the bitstreams created using this extension. In this paper, we propose a novel method to create scalable bitstreams that involve a backward compatible base layer in 4:2:0 format that can be handled by HEVC version 1 decoders and code additional layers to enhance the chroma resolution. The proposal codes 4:2:0 video in the base layer and the high resolution chroma components as auxiliary pictures as separate enhancement layers. The high resolution chroma components could optionally be predicted from the upsampled 4:2:0 chroma components of base layer. The simulations show that the proposed method achieves scalability with 9.5% coding efficiency penalty on average compared to single layer coding of 4:4:4 video. When compared to simulcast of 4:2:0 and 4:4:4 video, proposed method provides 38% gain on average. Proposed method makes services using high chroma fidelity easier to be deployed, due to the backwards compatibility to existing HEVC implementations with high coding efficiency.
Technologies used in today's video coding standards have been designed and optimized mainly f... more Technologies used in today's video coding standards have been designed and optimized mainly for Standard Definition (SD) resolutions and below. When moving to higher resolutions, data in video frames tend to become more correlated spatially. In this paper, we study how to take advantage of this phenomenon to lower computational requirements for High Definition (HD) video coding. A coding method
2014 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2014
ABSTRACT Color gamut scalability refers to coding a video in a layered manner where the base and ... more ABSTRACT Color gamut scalability refers to coding a video in a layered manner where the base and enhancement layers are coded in different color gamut spaces. Color gamut scalability and its relationship with spatial scalability are currently being studied for the scalable extension of HEVC (SHVC) to enable coding of ultra-high definition content having BT.2020 color gamut with 10-bit precision as an enhancement layer and high definition content having BT.709 color gamut with 8-bit precision as the base layer. In this paper, we propose to use the weighted prediction tool of the SHVC standard to map the color gamut of the base layer to the enhancement layer. In addition, we also propose a high-precision bit-depth mapping of the base layer to the enhancement layer that jointly performs upsampling with a bit-depth increase. Simulation results show that these two schemes improve the coding efficiency of the All Intra and Random Access configurations by about 6.8% and 3.6% on average, respectively, compared to a basic scheme where the bit-depth of the base layer is increased by simple bit-shifting. These gains are achieved by imposing no changes to the SHVC standard; hence make the proposed method very useful for practical use-cases as well.
2014 IEEE International Conference on Image Processing (ICIP), 2014
First version of the latest video coding standard, High Efficiency Video Coding (HEVC), only supp... more First version of the latest video coding standard, High Efficiency Video Coding (HEVC), only supports coding of video in YUV 4:2:0 chroma format. An extension of the standard that will support other chroma formats is currently under development, however, version 1 decoders will not be able to handle the bitstreams created using this extension. In this paper, we propose a novel method to create scalable bitstreams that involve a backward compatible base layer in 4:2:0 format that can be handled by HEVC version 1 decoders and code additional layers to enhance the chroma resolution. The proposal codes 4:2:0 video in the base layer and the high resolution chroma components as auxiliary pictures as separate enhancement layers. The high resolution chroma components could optionally be predicted from the upsampled 4:2:0 chroma components of base layer. The simulations show that the proposed method achieves scalability with 9.5% coding efficiency penalty on average compared to single layer coding of 4:4:4 video. When compared to simulcast of 4:2:0 and 4:4:4 video, proposed method provides 38% gain on average. Proposed method makes services using high chroma fidelity easier to be deployed, due to the backwards compatibility to existing HEVC implementations with high coding efficiency.
2008 IEEE International Conference on Acoustics, Speech and Signal Processing, 2008
Technologies used in today's video coding standards have been designed and optimized mainly for S... more Technologies used in today's video coding standards have been designed and optimized mainly for Standard Definition (SD) resolutions and below. When moving to higher resolutions, data in video frames tend to become more correlated spatially. In this paper, we study how to take advantage of this phenomenon to lower computational requirements for High Definition (HD) video coding. A coding method based on low complexity pruned transforms and interleaving of multiple transform coefficient blocks is proposed. An example implementation of this method in the context of H.264/AVC is also presented. Experimental results show that the proposed method maintains the high compression efficiency of H.264/AVC while significantly lowering the coding complexity of the codec.
2006 IEEE International Conference on Acoustics Speed and Signal Processing Proceedings, 2006
In this work, we propose novel encoder algorithms for the state-of-the-art video coding standard ... more In this work, we propose novel encoder algorithms for the state-of-the-art video coding standard H.264, to generate decoder friendly video bitstreams. Using the proposed algorithms, it is possible to generate bitstreams requiring significantly less decoding complexity, with negligible effect on picture quality. This is achieved by using novel algorithms for mode decision and motion estimation that bias easy-todecode motion vectors in a Rate-Distortion optimized fashion. Experimental results show that, more than 15% decoding complexity reduction is achieved with less than a 0.1 dB penalty on the average video quality. We believe that this approach has potential in various use cases especially in mobile multimedia systems, where the video decoder operation is often dominating the handsets power consumption.
2007 IEEE International Conference on Acoustics, Speech and Signal Processing - ICASSP '07, 2007
In this work, a novel sub-pixel interpolation algorithm is proposed for video coders targeted tow... more In this work, a novel sub-pixel interpolation algorithm is proposed for video coders targeted towards high resolution and high fidelity use cases. Proposed scheme is based on adapting the interpolation filter's symmetry assumptions in a Rate-Distortion-Optimized fashion, taking into account the coding rate and the statistical properties of each image of the video sequence. Experimental results show that, using the proposed algorithm a gain of up-to 1.1 dB is achieved compared to non-adaptive sub-pixel interpolation of H.264/AVC. Compared to other state-of-the-art adaptive sub-pixel interpolation methods, a gain of up-to 0.5 dB is achieved. Proposed scheme outperforms H.264/AVC for all test cases; however, improvement is more significant at high bitrates and at high resolutions. This is especially important for future video coding solutions targeting high fidelity video applications.
2008 3DTV Conference: The True Vision - Capture, Transmission and Display of 3D Video, 2008
The recent advances in capture, display and content representation technologies allow 3D video se... more The recent advances in capture, display and content representation technologies allow 3D video services to come to reality. In this paper, we present a prototype device that implements the emerging MVC standard on a portable device and achieves real-time 3D video operation. The developed prototype is based on Nokia N800 Internet Tablet and it is able to decode and display stereoscopic video simultaneously. To achieve this, an H.264/AVC decoder is first ported on the N800 environment with various optimizations and architectural changes, so that real-time decoding operation of two views is possible. The decoded pictures from different views are then interleaved and rendered on a screen with a parallax barrier. This way, the user is able to enjoy 3D video real-time on a mobile device. It is believed that this implementation is a realistic demonstration of the potential of upcoming mobile 3D video services, such as mobile 3DTV, mobile 3D video conferencing, etc.
2008 Ieee International Conference on Multimedia and Expo, May 26, 2008
In [1], Adaptive Prediction Error Coding (APEC) in spatial and frequency domain is proposed and s... more In [1], Adaptive Prediction Error Coding (APEC) in spatial and frequency domain is proposed and significantly improves the coding efficiency of video coders. However, this approach comes with the expense of increased encoding complexity because of the need to perform Rate Distortion Optimization (RDO) for each block, to decide whether the block is coded in spatial or frequency domain. In this work, we propose novel fast mode decision algorithm operating on macroblock and block level to reduce the encoding complexity of APEC. The proposed algorithm estimates the edge orientation of the residual block using spatial domain filtering, and based on the estimated edge orientation, reduces the number of candidates to be checked in RDO. Furthermore, proposed method includes an early termination step that stops searching the best candidate based on the difference between spatial and frequency domain coding. Experimental results show that the proposed fast mode decision algorithm can achieve averagely 90.7% encoding time reduction of APEC with only about 0.06 dB loss in coding efficiency.
2009 Ieee International Conference on Acoustics Speech and Signal Processing, 2009
In our previous work, we introduced Spatially Varying Transforms (SVT) for video coding, where th... more In our previous work, we introduced Spatially Varying Transforms (SVT) for video coding, where the location of the transform block within the macroblock is not fixed but varying. In this paper, we extend this concept and present a novel method, called Variable Block-size Spatially Varying Transforms (VBSVT). VBSVT utilizes Variable Block-size Transforms (VBT) in the SVT framework, and is shown to be more preferable for coding prediction error with different characteristics than fixed block-size SVT and also the standard methods that use fixed or adaptive block sizes at fixed spatial locations. In addition, VBSVT has similar decoding complexity with fixed block-size SVT and lower decoding complexity compared to standard methods as only a portion of the prediction error needs to be decoded. Experimental results show that, VBSVT achieves 4.1% gain over H.264/AVC on average over a wide range of test set. Gains become more significant at high quality levels and go up to 13.5%, which makes the proposed algorithm very suitable for future video coding solutions focusing on high fidelity applications.
2007 Ieee International Conference on Acoustics Speech and Signal Processing Icassp 07, Apr 15, 2007
In this work, a novel sub-pixel interpolation algorithm is proposed for video coders targeted tow... more In this work, a novel sub-pixel interpolation algorithm is proposed for video coders targeted towards high resolution and high fidelity use cases. Proposed scheme is based on adapting the interpolation filter's symmetry assumptions in a Rate-Distortion-Optimized fashion, taking into account the coding rate and the statistical properties of each image of the video sequence. Experimental results show that, using the proposed algorithm a gain of up-to 1.1 dB is achieved compared to non-adaptive sub-pixel interpolation of H.264/AVC. Compared to other state-of-the-art adaptive sub-pixel interpolation methods, a gain of up-to 0.5 dB is achieved. Proposed scheme outperforms H.264/AVC for all test cases; however, improvement is more significant at high bitrates and at high resolutions. This is especially important for future video coding solutions targeting high fidelity video applications.
2006 Ieee International Conference on Acoustics Speech and Signal Processing Proceedings, May 14, 2006
In this work, we propose novel encoder algorithms for the state-of-the-art video coding standard ... more In this work, we propose novel encoder algorithms for the state-of-the-art video coding standard H.264, to generate decoder friendly video bitstreams. Using the proposed algorithms, it is possible to generate bitstreams requiring significantly less decoding complexity, with negligible effect on picture quality. This is achieved by using novel algorithms for mode decision and motion estimation that bias easy-todecode motion vectors in a Rate-Distortion optimized fashion. Experimental results show that, more than 15% decoding complexity reduction is achieved with less than a 0.1 dB penalty on the average video quality. We believe that this approach has potential in various use cases especially in mobile multimedia systems, where the video decoder operation is often dominating the handsets power consumption.
Acoustics Speech and Signal Processing 1988 Icassp 88 1988 International Conference on, Mar 1, 2008
Technologies used in today's video coding standards have been designed and optimized mainly for S... more Technologies used in today's video coding standards have been designed and optimized mainly for Standard Definition (SD) resolutions and below. When moving to higher resolutions, data in video frames tend to become more correlated spatially. In this paper, we study how to take advantage of this phenomenon to lower computational requirements for High Definition (HD) video coding. A coding method based on low complexity pruned transforms and interleaving of multiple transform coefficient blocks is proposed. An example implementation of this method in the context of H.264/AVC is also presented. Experimental results show that the proposed method maintains the high compression efficiency of H.264/AVC while significantly lowering the coding complexity of the codec.
2014 Ieee International Conference on Image Processing, Oct 27, 2014
First version of the latest video coding standard, High Efficiency Video Coding (HEVC), only supp... more First version of the latest video coding standard, High Efficiency Video Coding (HEVC), only supports coding of video in YUV 4:2:0 chroma format. An extension of the standard that will support other chroma formats is currently under development, however, version 1 decoders will not be able to handle the bitstreams created using this extension. In this paper, we propose a novel method to create scalable bitstreams that involve a backward compatible base layer in 4:2:0 format that can be handled by HEVC version 1 decoders and code additional layers to enhance the chroma resolution. The proposal codes 4:2:0 video in the base layer and the high resolution chroma components as auxiliary pictures as separate enhancement layers. The high resolution chroma components could optionally be predicted from the upsampled 4:2:0 chroma components of base layer. The simulations show that the proposed method achieves scalability with 9.5% coding efficiency penalty on average compared to single layer coding of 4:4:4 video. When compared to simulcast of 4:2:0 and 4:4:4 video, proposed method provides 38% gain on average. Proposed method makes services using high chroma fidelity easier to be deployed, due to the backwards compatibility to existing HEVC implementations with high coding efficiency.
Technologies used in today's video coding standards have been designed and optimized mainly f... more Technologies used in today's video coding standards have been designed and optimized mainly for Standard Definition (SD) resolutions and below. When moving to higher resolutions, data in video frames tend to become more correlated spatially. In this paper, we study how to take advantage of this phenomenon to lower computational requirements for High Definition (HD) video coding. A coding method
2014 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2014
ABSTRACT Color gamut scalability refers to coding a video in a layered manner where the base and ... more ABSTRACT Color gamut scalability refers to coding a video in a layered manner where the base and enhancement layers are coded in different color gamut spaces. Color gamut scalability and its relationship with spatial scalability are currently being studied for the scalable extension of HEVC (SHVC) to enable coding of ultra-high definition content having BT.2020 color gamut with 10-bit precision as an enhancement layer and high definition content having BT.709 color gamut with 8-bit precision as the base layer. In this paper, we propose to use the weighted prediction tool of the SHVC standard to map the color gamut of the base layer to the enhancement layer. In addition, we also propose a high-precision bit-depth mapping of the base layer to the enhancement layer that jointly performs upsampling with a bit-depth increase. Simulation results show that these two schemes improve the coding efficiency of the All Intra and Random Access configurations by about 6.8% and 3.6% on average, respectively, compared to a basic scheme where the bit-depth of the base layer is increased by simple bit-shifting. These gains are achieved by imposing no changes to the SHVC standard; hence make the proposed method very useful for practical use-cases as well.
2014 IEEE International Conference on Image Processing (ICIP), 2014
First version of the latest video coding standard, High Efficiency Video Coding (HEVC), only supp... more First version of the latest video coding standard, High Efficiency Video Coding (HEVC), only supports coding of video in YUV 4:2:0 chroma format. An extension of the standard that will support other chroma formats is currently under development, however, version 1 decoders will not be able to handle the bitstreams created using this extension. In this paper, we propose a novel method to create scalable bitstreams that involve a backward compatible base layer in 4:2:0 format that can be handled by HEVC version 1 decoders and code additional layers to enhance the chroma resolution. The proposal codes 4:2:0 video in the base layer and the high resolution chroma components as auxiliary pictures as separate enhancement layers. The high resolution chroma components could optionally be predicted from the upsampled 4:2:0 chroma components of base layer. The simulations show that the proposed method achieves scalability with 9.5% coding efficiency penalty on average compared to single layer coding of 4:4:4 video. When compared to simulcast of 4:2:0 and 4:4:4 video, proposed method provides 38% gain on average. Proposed method makes services using high chroma fidelity easier to be deployed, due to the backwards compatibility to existing HEVC implementations with high coding efficiency.
2008 IEEE International Conference on Acoustics, Speech and Signal Processing, 2008
Technologies used in today's video coding standards have been designed and optimized mainly for S... more Technologies used in today's video coding standards have been designed and optimized mainly for Standard Definition (SD) resolutions and below. When moving to higher resolutions, data in video frames tend to become more correlated spatially. In this paper, we study how to take advantage of this phenomenon to lower computational requirements for High Definition (HD) video coding. A coding method based on low complexity pruned transforms and interleaving of multiple transform coefficient blocks is proposed. An example implementation of this method in the context of H.264/AVC is also presented. Experimental results show that the proposed method maintains the high compression efficiency of H.264/AVC while significantly lowering the coding complexity of the codec.
2006 IEEE International Conference on Acoustics Speed and Signal Processing Proceedings, 2006
In this work, we propose novel encoder algorithms for the state-of-the-art video coding standard ... more In this work, we propose novel encoder algorithms for the state-of-the-art video coding standard H.264, to generate decoder friendly video bitstreams. Using the proposed algorithms, it is possible to generate bitstreams requiring significantly less decoding complexity, with negligible effect on picture quality. This is achieved by using novel algorithms for mode decision and motion estimation that bias easy-todecode motion vectors in a Rate-Distortion optimized fashion. Experimental results show that, more than 15% decoding complexity reduction is achieved with less than a 0.1 dB penalty on the average video quality. We believe that this approach has potential in various use cases especially in mobile multimedia systems, where the video decoder operation is often dominating the handsets power consumption.
2007 IEEE International Conference on Acoustics, Speech and Signal Processing - ICASSP '07, 2007
In this work, a novel sub-pixel interpolation algorithm is proposed for video coders targeted tow... more In this work, a novel sub-pixel interpolation algorithm is proposed for video coders targeted towards high resolution and high fidelity use cases. Proposed scheme is based on adapting the interpolation filter's symmetry assumptions in a Rate-Distortion-Optimized fashion, taking into account the coding rate and the statistical properties of each image of the video sequence. Experimental results show that, using the proposed algorithm a gain of up-to 1.1 dB is achieved compared to non-adaptive sub-pixel interpolation of H.264/AVC. Compared to other state-of-the-art adaptive sub-pixel interpolation methods, a gain of up-to 0.5 dB is achieved. Proposed scheme outperforms H.264/AVC for all test cases; however, improvement is more significant at high bitrates and at high resolutions. This is especially important for future video coding solutions targeting high fidelity video applications.
2008 3DTV Conference: The True Vision - Capture, Transmission and Display of 3D Video, 2008
The recent advances in capture, display and content representation technologies allow 3D video se... more The recent advances in capture, display and content representation technologies allow 3D video services to come to reality. In this paper, we present a prototype device that implements the emerging MVC standard on a portable device and achieves real-time 3D video operation. The developed prototype is based on Nokia N800 Internet Tablet and it is able to decode and display stereoscopic video simultaneously. To achieve this, an H.264/AVC decoder is first ported on the N800 environment with various optimizations and architectural changes, so that real-time decoding operation of two views is possible. The decoded pictures from different views are then interleaved and rendered on a screen with a parallax barrier. This way, the user is able to enjoy 3D video real-time on a mobile device. It is believed that this implementation is a realistic demonstration of the potential of upcoming mobile 3D video services, such as mobile 3DTV, mobile 3D video conferencing, etc.
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Papers by Kemal Ugur