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r-d optimization of EEd-based Compressed Image Using Linear regression 1

International Conference on Computational Vision and robotics (ICCVr)

作者： Mohanty, Bibhuprasad Sahoo, Madhusmita Mohapatra, Sudipta Siksha O Anusandhana Univ Fac Engn Dept ECE ITER Bhubaneswar Orissa India Indian Inst Technol Dept E&ECE Kharagpur 721302 W Bengal India

ISBN: (数字)9788132221968

ISBN: (纸本)9788132221968;9788132221951

Image compression technique minimizes the size in bytes of a graphics file without degrading the quality of the image to an unacceptable visual level. The performance is driven by the trade-off between rate (r), distortion (d), and complexity of the coding algorithm. This piece of work deals with the simple yet effective method of image-dependent r-d optimization by optimizing the cost function of the constrained Lagrangian multiplier. A simple linear regression is employed to estimate the cost and the slope of the convex haul in the r-d plane. The image is compressed by SPIHT algorithm after it was subjected to anisotropic diffusion to provide a powerful zero tree pyramid. The Perona-Malik diffusion preserves the edge and boundary information by smoothening the whole image. Extensive simulation for the proposed diffusion platform provides better results in terms of PSNr and visual quality, and the estimation approximates the actual values with minimum residuals.

关键词： Anisotropicdiffusion SPHIT EEd r-d optimization Linear regression OLS

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New r-d optimization Criterion for Fast Mode decision Algorithms in Video Coding and Transrating

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IEEE TrANSACTIONS ON CIrCUITS ANd SYSTEMS FOr VIdEO TECHNOLOGY 2016年第4期26卷 696-710页

作者： Aminlou, Alireza Hashemi, Mahmoud reza Gabbouj, Moncef Zeng, Bing Fatemi, Omid Univ Tehran Tehran *** Iran Tampere Univ Technol Dept Signal Proc Tampere 33720 Finland Univ Tehran Sch Elect & Comp Engn Tehran *** Iran Hong Kong Univ Sci & Technol Dept Elect & Comp Engn Hong Kong Hong Kong Peoples R China

Mode decision has a significant effect on the quality and complexity of video coding. It is even more challenging when generating multiple bitstreams with different bitrates (Brs) in, for example, dynamic adaptive streaming for HTTP or transrating systems. Full search and simplified fast search mode decision (Md) methods either suffer from a high computational complexity or have a negative impact on quality. Furthermore, mode selection in conventional approaches strongly depends on the quantization parameter (QP). Hence, modes that have been selected for high Br compression may not be suitable for low Br when transrating a bitstream. In this paper, we propose a rate-distortion (r-d)-optimized criterion for fast Md algorithms. The proposed cost function, when adopted in different fast Md algorithms, not only improves the r-d performance by up to 6.6% in terms of Bjontegaard delta rate, but also reduces the execution time of the encoder by up to 6.8%. We also show that modes selected by the proposed criterion are less sensitive to changes in Br or QP. As a result, the same modes in an encoded bitstream may be used even after transrating using requantization, resulting in a significant r-d performance improvement of up to 33.3%.

关键词： dynamic adaptive streaming for HTTP (dASH) H.264/advanced video coding (AVC) mode decision (Md) rate-distortion (r-d) model r-d optimization video transrating

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Frame-level ρ-domain r-d optimization in H.264

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IEICE TrANSACTIONS ON INFOrMATION ANd SYSTEMS 2007年第5期E90D卷 872-876页

作者： dong, Yutao Fang, Xiangzhong Yang, Jing Shanghai Jiao Tong Univ Inst Image Commun & Informat Proc Shanghai 200240 Peoples R China

The frame-level r-d optimization in H.264 is very important in video storage scenarios. Among all of the sub-optimal algorithms, a greedy iteration algorithm (GIA) can best lower the computational complexity of frame-level r-d optimization. In order to further lower the computational complexity, a p-domain frame-level r-d optimization algorithm is proposed in this letter. different from GIA, every frame's rate and distortion can be estimated accurately without actual encoding in our proposed algorithm. Simulation results show that our proposed algorithm can lower the computational complexity greatly with negligible variation in peak signal-to-noise ratio (PSNr) compared with GIA.

关键词： rho-domain r-d optimization H. 264 frame-level

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Iterative r-d optimization of H.264

Iterative R-D optimization of H.264

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33rd IEEE International Conference on Acoustics, Speech and Signal Processing

作者： An, Cheolhong Nguyen, Truong Q. Univ Calif San Diego ECE Dept La Jolla CA 92093 USA

ISBN: (纸本)9781424414833

In this paper, we apply the primal-dual decomposition and subgradient projection methods to solve the rate-distortion optimization problem with the constant bit rate constraint. The primal decomposition method enables spatial or temporal prediction dependency within a Group Of Picture (GOP) to be processed in the master primal problem. As a result, we can apply the dual decomposition to minimize independently the Lagrangian cost of all the MBs using the reference software model of H.264. Furthermore, the optimal Lagrange multiplier lambda* is iteratively derived from the solution of the dual problem. As an example, we derive the optimal bit allocation condition with the consideration of temporal prediction dependency among the pictures. Experimental results show that the proposed method achieves better performance than the reference software model of H.264 with rate control for given bit constraint.

关键词： H.264 r-d optimization optimal bit allocation primal-dual decomposition rate control

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An efficient FGS to MPEG-1/2/4 single layer transcoder with r-d optimized multi-layer streaming technique for video quality improvement

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JOUrNAL OF THE CHINESE INSTITUTE OF ENGINEErS 2007年第6期30卷 1059-1070页

作者： Shih-Hao Wang Wei-Lin Chen Tihao Chiang Natl Chiao Tung Univ Inst Elect Hsinchu 30039 Taiwan

The need for interoperability poses a challenge with the widespread use of multiple video formats. A Multi Layer Streaming-Simplified dCT domain Transcoder (MLS-SddT) is proposed to achieve efficient transcoding and video quality improvement. However, an efficient architecture is needed to handle drifting errors. The MLS-SddT algorithm addresses these issues by proposing: (1) an FGS compatible Simplified dCT domain Transcoder (FGS-SddT) architecture for MPEG-1/2/4 single layer transcoding, and (2) an r-d optimized multi-layer streaming technique for video quality improvement. To support efficient transcoding from FGS to MPEG-1/2/4, the FGS-SddT adopts low complexity Simplified dCT domain Transcoder (SddT) architecture as an FGS compatible SddT. To resolve the serious error-drifting problem from SddT, especially for heterogeneous transcoding, a mathematical analysis of the error-drifting problem is provided and a solution by multi-layer streaming is adopted. The multi-layer streaming approach pre-computes the errors according to the mathematical analysis and encodes the errors as the second enhancement layer for error compensation. For different network conditions, an r-d optimized model is used to improve the bit allocation in the two enhancement layers for better r-d performance. Our experiments show that the MLS-SddT can deliver 1.4 similar to 7.0 dB PSNr improvement for MPEG-1 and 1.9 similar to 8.6 dB improvement for MPEG-2 as compared to the SddT. For FGS to MPEG-4 single layer transcoding, the MLS-SddT can achieve minor PSNr loss (0.0 similar to 0.4 dB) with lower computational complexity as compared to the SddT approach.

关键词： transcoding MPEG-4 FGS MPEG-1/2/4 multi-layer streaming r-d optimization

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rate-distortion modeling for efficient H.264/AVC encoding

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IEEE TrANSACTIONS ON CIrCUITS ANd SYSTEMS FOr VIdEO TECHNOLOGY 2007年第5期17卷 530-543页

作者： Tu, Yu-Kuang Yang, Jar-Feff Sun, Ming-Ting Natl Cheng Kung Univ Dept Elect Engn Tainan 701 Taiwan Natl Cheng Kung Univ Inst Comp & Commun Engn Media Proc Lab Tainan 701 Taiwan Natl Cheng Kung Univ Dept Elect Engn Tainan 701 Taiwan Univ Washington Dept Elect Engn Informat Proc Lab Seattle WA 98195 USA

The rate-distortion (r-d) optimization technique plays an important role in optimizing video encoders. Modeling the rate and distortion functions accurately in acceptable complexity helps to make the optimization more practical. In this paper, we propose a bit-rate estimation function and a distortion measure by modeling the transform coefficients with spatial-domain variance. Furthermore, with quantization-based thresholding to determine the number, the absolute sum, and the squared sum of transform coefficients, the simplified transform-domain r-d measurement is introduced. The proposed algorithms can reduce the computation complexity for the r-d optimized mode-decision by using the new cost function evolving from the simplified transform-domain r-d model. Based on the proposed estimations, a rate-control scheme in the macroblock layer is also proposed to improve the coding efficiency.

关键词： bit-allocation H.264/AVC mode decision rate-control rate-distortion (r-d) modeling r-d optimization

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Macroblock Level Bits Allocation for depth Maps in 3-d Video Coding

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JOUrNAL OF SIGNAL PrOCESSING SYSTEMS FOr SIGNAL IMAGE ANd VIdEO TECHNOLOGY 2014年第1期74卷 127-135页

作者： Xiao, Jimin Tillo, Tammam Yuan, Hui Zhao, Yao Univ Liverpool Dept Elect Engn & Elect Liverpool L69 3BX Merseyside England Xian Jiaotong Liverpool Univ Dept Elect & Elect Engn Suzhou Peoples R China Shandong Univ Sch Informat Sci & Engn Jinan 250100 Peoples R China Beijing Jiaotong Univ Inst Informat Sci Beijing Peoples R China

For 3-d videos, one commonly used representation method is texture videos plus depth maps for several selected viewpoints, whereas the other viewpoints are synthesized based on the available texture videos and depth maps with the depth-image-based rendering (dIBr) technique. As both the quality of the texture videos and depth maps will affect the quality of the synthesized views, bits allocation for the depth maps become indispensable. The existing bits allocation approaches are either inaccurate or requiring pre-encoding and analyzing in temporal dimension, making them unsuitable for the real-time applications. Motivated by the fact that different regions of the depth maps have different impacts on the synthesized image quality, a real-time macroblock level bits allocation approach is proposed, where different macroblocks of the depth maps are encoded with different quantization parameters and coding modes. As the bits allocation granularity is fine, the r-d performance of the proposed approach outperforms other bits allocation approaches significantly, while no additional pre-encoding delay is caused. Specifically, it can save more than 10% overall bit rate comparing with Morvan's full search approach, while maintaining the same synthesized view quality.

关键词： 3-d video coding Bits allocation Macroblock level real-time r-d optimization

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.rate-distortion-authentication optimized streaming of authenticated video

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IEEE TrANSACTIONS ON CIrCUITS ANd SYSTEMS FOr VIdEO TECHNOLOGY 2007年第5期17卷 544-557页

作者： Zhang, Zhishou Sun, Qibin Wong, Wai-Choong Apostolopoulos, John Wee, Susie Inst Infocomm Res I2R Singapore Singapore Natl Univ Singapore Dept Elect & Comp Engn Singapore 117548 Singapore Hewlett Packard Labs Palo Alto CA 94304 USA

We define authenticated video as decoded video that results from those received packets whose authenticities have been verified. Generic data stream authentication methods usually impose overhead and dependency among packets for verification. Therefore, the conventional rate-distortion (r-d) optimized video streaming techniques produce highly sub-optimal r-d performance for authenticated video, since they do not account for the overhead and additional dependencies for authentication. In this paper, we study this practical problem and propose an rate-distortion-Authentication (r-d-A) optimized streaming technique for authenticated video. Based on packets' importance in terms of both video quality and authentication dependencies, the proposed technique computes a packet transmission schedule that minimizes the expected end-to-end distortion of the authenticated video at the receiver subject to a constraint on the average transmission rate. Simulation results based on H.264 JM 10.2 and NS-2 demonstrate that our proposed r-d-A optimized streaming technique substantially outperforms both prior (authentication-unaware) r-d optimized streaming techniques and data stream authentication techniques. In particular, when the channel capacity is below the source rate, the PSNr of authenticated video quickly drops to unacceptable levels using conventional r-d optimized streaming techniques, while the proposed r-d-A optimization technique still maintains optimized video quality. Furthermore, we examine a low-complexity version of the proposed algorithm, and also an enhanced version which accounts for the multiple deadlines associated with each packet, which is introduced by stream authentication.

关键词： butterfly digital signature r-d optimization r-d-A optimization stream authentication

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Illumination Estimation and Compensation of Low Frame rate Video Sequences for Wavelet-Based Video Compression

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IEEE TrANSACTIONS ON IMAGE PrOCESSING 2019年第9期28卷 4313-4327页

作者： Haghighat, Maryam Mathew, reji Naman, Aous Taubman, david Univ New South Wales Sch Elect Engn & Telecommun Sydney NSW 2052 Australia

In this paper, we are interested in the compression of image sets or video with considerable changes in illumination. We develop a framework to decompose frames into illumination fields and texture in order to achieve sparser representations of frames which is beneficial for compression. Illumination variations or contrast ratio factors among frames are described by a full resolution multiplicative field. First, we propose a Lifting-based Illumination Adaptive Transform (LIAT) framework which incorporates illumination compensation to temporal wavelet transforms. We estimate a full resolution illumination field, taking heed of its spatial sparsity by a rate-distortion (r-d) driven framework. An affine mesh model is also developed as a point of comparison. We find the operational coding cost of the subband frames by modeling a typical t + 2d wavelet video coding system. While our general findings on r-d optimization are applicable to a range of coding frameworks, in this paper, we report results based on employing JPEG 2000 coding tools. The experimental results highlight the benefits of the proposed r-d driven illumination estimation and compensation in comparison with alternative scalable coding methods and non-scalable coding schemes of AVC and HEVC employing weighted prediction.

关键词： Wavelet-based compression Illumination estimation r-d optimization Scalable video coding

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Trellis-based r-d optimal quantization in H.263+

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IEEE TrANSACTIONS ON IMAGE PrOCESSING 2000年第8期9卷 1431-1434页

作者： Wen, JT Luttrell, M Villasenor, J Packet Video Corp San Diego CA 92121 USA Univ Calif Los Angeles Dept Elect Engn Los Angeles CA 90095 USA

We describe a trellis-based algorithm which enables r-d optimum quantization decisions in the H.263+ video coding standard. The algorithm allows the quantization decisions for all coefficients in a block to be made jointly, and experiments conducted using H.263+ for video coding rates of 40-50 kbps show an average improvement of 3.5% in bitrate relative to implementations which Follow the International Telecommunications Union (ITU) Test Model specifications in making quantization decisions.

关键词： dynamic programming H.263+ r-d optimization video coding

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