The Experts below are selected from a list of 52302 Experts worldwide ranked by ideXlab platform
Hsuehming Hang - One of the best experts on this subject based on the ideXlab platform.
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fast Mode Decision algorithm for residual quadtree coding in hevc
Visual Communications and Image Processing, 2011Co-Authors: Suwei Teng, Hsuehming Hang, Yifu ChenAbstract:High Efficiency Video Coding (HEVC) is an in-progress next generation video coding standard. It has a similar basic structure to the ITU/MPEG H.264/AVC coder but with further enhancement on each coding tool to increase compression efficiency. Thus, a Residual Quadtree (RQT) coding scheme is adopted in the conventional transform coding procedure. The cost is the additional computation complexity when compared to the fixed-size transform. In this paper, we design a fast algorithm for Residual Quadtree Mode Decision. Considering the Rate-Distortion efficiency, we replace the original depth-first Mode Decision process by a Merge-and-Split Decision process. Furthermore, because a substantial numbers of zero-blocks are produced after quantization and Mode Decision, we reduce the unnecessary computation by using the inheritance property of zero-blocks. In addition, for nonzero-blocks, two early termination schemes are developed for both TU Merge and TU Split procedures, respectively. Comparing to HM 2.0, our method saves the RQT encoding time from 42% to 55% for a number of test videos with negligible coding loss.
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fast context adaptive Mode Decision algorithm for scalable video coding with combined coarse grain quality scalability cgs
2010Co-Authors: Hungchih Lin, Wenhsiao Peng, Hsuehming HangAbstract:To speed up the H.264/MPEG scalable video coding (SVC) encoder, we propose a layer-adaptive intra/inter Mode de- cision algorithm and a motion search scheme for the hierarchical B-frames in SVC with combined coarse-grain quality scalability (CGS) and temporal scalability. To reduce computation but maintain the same level of coding efficiency, we examine the rate- distortion (R-D) performance contributed by different coding Modes at the enhancement layers (EL) and the Mode conditional probabilities at different temporal layers. For the intra prediction on inter frames, we can reduce the number of Intra4×4/Intra8×8 prediction Modes by 50% or more, based on the reference/base layer intra prediction directions. For the EL inter prediction, the look-up tables containing inter prediction candidate Modes are designed to use the macroblock (MB) coding Mode de- pendence and the reference/base layer quantization parameters (Qp). In addition, to avoid checking all motion estimation (ME) reference frames, the base layer (BL) reference frame index is selectively reused. And according to the EL MB partition, the BL motion vector can be used as the initial search point for the EL ME. Compared with Joint Scalable Video Model 9.11, our proposed algorithm provides a 20× speedup on encoding the EL and an 85% time saving on the entire encoding process with negligible loss in coding efficiency. Moreover, compared with other fast Mode Decision algorithms, our scheme can demonstrate a 7-41% complexity reduction on the overall encoding process. Index Terms—Coarse-grain quality scalability, encoder opti- mization, fast Mode Decision, scalable video coding (SVC).
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Fast Context-Adaptive Mode Decision Algorithm for Scalable Video Coding With Combined Coarse-Grain Quality Scalability (CGS) and Temporal Scalability
IEEE Transactions on Circuits and Systems for Video Technology, 2010Co-Authors: Wenhsiao Peng, Hsuehming HangAbstract:To speed up the H.264/MPEG scalable video coding (SVC) encoder, we propose a layer-adaptive intra/inter Mode Decision algorithm and a motion search scheme for the hierarchical B-frames in SVC with combined coarse-grain quality scalability (CGS) and temporal scalability. To reduce computation but maintain the same level of coding efficiency, we examine the rate-distortion (R-D) performance contributed by different coding Modes at the enhancement layers (EL) and the Mode conditional probabilities at different temporal layers. For the intra prediction on inter frames, we can reduce the number of Intra4×4/Intra 8×8 prediction Modes by 50% or more, based on the reference/base layer intra prediction directions. For the EL inter prediction, the look-up tables containing inter prediction candidate Modes are designed to use the macroblock (MB) coding Mode dependence and the reference/base layer quantization parameters (Qp). In addition, to avoid checking all motion estimation (ME) reference frames, the base layer (BL) reference frame index is selectively reused. And according to the EL MB partition, the BL motion vector can be used as the initial search point for the EL ME. Compared with Joint Scalable Video Model 9.11, our proposed algorithm provides a 20× speedup on encoding the EL and an 85% time saving on the entire encoding process with negligible loss in coding efficiency. Moreover, compared with other fast Mode Decision algorithms, our scheme can demonstrate a 7-41% complexity reduction on the overall encoding process.
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layer adaptive Mode Decision and motion search for scalable video coding with combined coarse granular scalability cgs and temporal scalability
International Conference on Image Processing, 2007Co-Authors: Hungchih Lin, Wenhsiao Peng, Hsuehming HangAbstract:In this paper, we propose a layer-adaptive Mode Decision algorithm and a motion search scheme for the scalable video coding (SVC) with combined coarse granular scalability (CGS) and temporal scalability. To speed up the encoder while minimizing the loss in coding efficiency, our layer-adaptive Mode Decision recursively refers to the prediction Modes and quantization parameter of the reference/base layer to minimize the number of Modes tested at the enhancement layer. Moreover, our motion search scheme adaptively reuses the reference frame indices of the base layer and determines the initial search point using the motion vector at the base layer or the motion vector predictor at the enhancement layer. As compared with JSVM 8, the proposed algorithms provide up to 75% overall time saving and more than 85% time reduction for encoding enhancement layers with negligible loss in coding efficiency.
K P Lim - One of the best experts on this subject based on the ideXlab platform.
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fast Mode Decision algorithm for intraprediction in h 264 avc video coding
IEEE Transactions on Circuits and Systems for Video Technology, 2005Co-Authors: F Pan, Xiao Lin, Susanto Rahardja, K P LimAbstract:The H.264/AVC video coding standard aims to enable significantly improved compression performance compared to all existing video coding standards. In order to achieve this, a robust rate-distortion optimization (RDO) technique is employed to select the best coding Mode and reference frame for each macroblock. As a result, the complexity and computation load increase drastically. This paper presents a fast Mode Decision algorithm for H.264/AVC intraprediction based on local edge information. Prior to intraprediction, an edge map is created and a local edge direction histogram is then established for each subblock. Based on the distribution of the edge direction histogram, only a small part of intraprediction Modes are chosen for RDO calculation. Experimental results show that the fast intraprediction Mode Decision scheme increases the speed of intracoding significantly with negligible loss of peak signal-to-noise ratio.
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fast intra Mode Decision algorithm for h 264 avc video coding
International Conference on Image Processing, 2004Co-Authors: F Pan, L S Rahardja, K P Lim, Ce Zhu, Z LiangAbstract:The emerging H.264-AVC video coding standard aims to significantly improve compression performance compared to all existing video coding standards. In order to achieve this, a robust rate-distortion optimization (RDO) technique is employed to select the best coding Mode and reference frame for each macroblock. As a result, the complexity and computation load increase drastically. This paper presents a fast Mode Decision algorithm for H.264 intra prediction based on local edge information. Prior to intra prediction, an edge map is created and a local edge direction histogram is then established for each sub-block. Based on the distribution of the edge direction histogram, only a small part of intra prediction Modes are chosen for RDO calculation. Experimental results show that the last intra Mode Decision scheme increases the speed of intra coding significantly with negligible loss of PSNR.
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a directional field based fast intra Mode Decision algorithm for h 264 video coding
International Conference on Multimedia and Expo, 2004Co-Authors: F Pan, Xiao Lin, Susanto Rahardja, K P LimAbstract:The H.264 video coding standard can achieve considerably higher coding efficiency than previous standards. In order to achieve this, a robust rate-distortion optimization (RDO) technique is employed to select the best coding Mode for each macroblock. As a result. the encoder complexity is increased considerably. This paper presents a directional field based fast intra Mode Decision algorithm to improve the encoder's efficiency. Prior to intra prediction, the directional field is calculated for all the block size to decide the dominant edge direction in the blocks. Based on the edge direction information, only a small number of prediction Modes are chosen for RDO calculation. Experimental results show that the fast intra Mode Decision algorithm increases the speed of intra coding significantly with negligible loss of PSNR
Huanqiang Zeng - One of the best experts on this subject based on the ideXlab platform.
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fast multiview video coding using adaptive prediction structure and hierarchical Mode Decision
IEEE Transactions on Circuits and Systems for Video Technology, 2014Co-Authors: Huanqiang Zeng, Xiaolan Wang, Jing Chen, Yan ZhangAbstract:The multiview video coding (MVC) adopts hierarchical B picture prediction structure and offers many prediction Modes to effectively remove the spatial, temporal, and inter-view redundancies inherited in multiview video (MVV), but at the price of extremely high computational complexity. To address this problem, a fast MVC method by jointly using adaptive prediction structure (APS) and hierarchical Mode Decision (HMD) is proposed in this paper. The complexity reduction is achieved by: 1) designing four APSs for different MVV contents based on the fact that the contribution of the inter-view prediction varies from sequence to sequence and 2) developing an HMD scheme based on the observation that the relationship between the rate distortion (RD) cost and size of prediction Mode is a unimodal function. In particular, for the current group of picture of the input MVV, the prediction structure is adaptively selected based on its characteristic, which is measured by the ratio of the average RD cost of the base view frames to the sum of the average RD cost of the base view frames and that of anchor frames in nonbase views, and then an HMD scheme is further performed to skip the checking process of those unlikely Modes. The experimental results have shown that compared with the exhaustive Mode Decision in the MVC, the proposed algorithm achieves a reduction of the computational complexity by 83.49% on average, whereas incurring only a 0.086 dB loss in Bjontegaard delta peak signal-to-noise ratio and 2.97% increment on the total Bjontegaard delta bit rate.
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hierarchical intra Mode Decision for h 264 avc
IEEE Transactions on Circuits and Systems for Video Technology, 2010Co-Authors: Huanqiang Zeng, Canhui CaiAbstract:The intra Mode prediction via exhaustive Mode Decision exploited in the H.264/advanced video coding effectively improves the coding efficiency, but at the expense of yielding higher computational complexity. In this letter, a fast intra Mode Decision algorithm, called the hierarchical intra Mode Decision (HIMD), is proposed to speed up the Mode Decision process by reducing the number of Modes required to be checked for each macroblock. The novelty of the proposed HIMD algorithm lies at the following accounts. 1) An early Decision with adaptive thresholding is developed for the Mode Decision of the luma component. 2) The candidate Modes are selected according to their Hadamard distances and prediction directions. 3) Only one of the hierarchical paths will be chosen to compute its least rate-distortion cost. Experimental results have shown that the proposed HIMD algorithm achieves a reduction of 85.75% computational complexity on average, while incurring only 0.164 dB loss in peak signal-to-noise ratio (PSNR) and 2.336% increment on the total bit rate compared with that of exhaustive Mode Decision, which is a default approach set in the joint Model reference software.
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fast Mode Decision for h 264 avc based on macroblock motion activity
IEEE Transactions on Circuits and Systems for Video Technology, 2009Co-Authors: Huanqiang Zeng, Canhui CaiAbstract:The intra-Mode and inter-Mode predictions have been made available in H.264/AVC for effectively improving coding efficiency. However, exhaustively checking for all the prediction Modes for identifying the best one (commonly referred to as exhaustive Mode Decision) greatly increases computational complexity. In this paper, a fast Mode Decision algorithm, called the motion activity-based Mode Decision (MAMD), is proposed to speed up the encoding process by reducing the number of Modes required to be checked in a hierarchical manner, and is as follows. For each macroblock, the proposed MAMD algorithm always starts with checking the rate-distortion (RD) cost computed at the SKIP Mode for a possible early termination, once the RD cost value is below a predetermined ldquolowrdquo threshold. On the other hand, if the RD cost exceeds another ldquohighrdquo threshold, then this indicates that only the intra Modes are worthwhile to be checked. If the computed RD cost falls between the above-mentioned two thresholds, the remaining seven Modes, which are classified into three motion activity classes in our work, will be examined, and only one of the three classes will be chosen for further Mode checking. The above-mentioned motion activity can be quantitatively measured, which is equal to the maximum city-block length of the motion vector taken from a set of adjacent macroblocks (i.e., region of support, ROS). This measurement is then used to determine the most possible motion-activity class for the current macroblock. Experimental results have shown that, on average, the proposed MAMD algorithm reduces the computational complexity by 62.96%, while incurring only 0.059 dB loss in PSNR (peak signal-to-noise ratio) and 0.19% increment on the total bit rate compared to that of exhaustive Mode Decision, which is a default approach set in the JM reference software.
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a novel fast Mode Decision for the h 264 avc based on local macroblock motion activity
International Conference on Image and Graphics, 2007Co-Authors: Huanqiang Zeng, Canhui CaiAbstract:The intra- and inter-prediction techniques have been effectively exploited in the H.264/AVC for significantly improving the coding efficiency. However, exhaustively searching for the optimal prediction Mode vastly increases its computational complexity. To decrease the computational complexity of the Mode Decision process, a novel fast Mode Decision algorithm is proposed in this paper to speed up the encoding process by predicting the Mode of the current macroblock based on the motion activity of the neighboring macroblocks. The proposed algorithm has two main stages. First, the SKIP Mode is utilized as an early termination mechanism to terminate any further checking of other Modes. This is quite effective for those regions with low-motion activity. If the SKIP Mode is not met, the local macroblocks' motion activities will be identified in terms of motion-vector city-block length. Experimental results have shown that the proposed algorithm achieves a reduction of 56% computational complexity on average, while introducing only 0.059 dB loss in PSNR and 0.2% increment on the total bit rate compared with that of exhaustive trying out all possible Modes, being set as the default in the original JM reference software.
Changyun Wen - One of the best experts on this subject based on the ideXlab platform.
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fast Mode Decision for coarse granular scalability via switched candidate Mode set
International Conference on Multimedia and Expo, 2007Co-Authors: Changyun Wen, Shoulie XieAbstract:This paper presents an improved fast Mode Decision algorithm for coarse grain scalability (CGS). The modified fast Mode Decision algorithm extends previous work to provide better encoder complexity reduction with insignificant degradation in picture quality. The candidate Mode set is adaptive to the quantization parameter difference between a layer and its "base layer". Furthermore, the proposed scheme fully utilizes the statistics of Mode transition between a layer and its "base layer" when the quantization parameter difference between these two layers is small. Simulation results demonstrate that the proposed scheme provides up to 64% of time saving compared with the original SVC encoder.
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fast Mode Decision algorithm for inter frame coding in fully scalable video coding
IEEE Transactions on Circuits and Systems for Video Technology, 2006Co-Authors: Changyun WenAbstract:Scalable video coding is an ongoing standard, and the current working draft (WD) is an extension of H.264/AVC. In the WD, an exhaustive search technique is employed to select the best coding Mode for each macroblock. This technique achieves the highest possible coding efficiency, but it results in extremely large encoding time which obstructs it from practical use. This paper proposes a fast Mode Decision algorithm for inter-frame coding for spatial, coarse grain signal-to-noise ratio, and temporal scalability. It makes use of the Mode-distribution correlation between the base layer and enhancement layers. Specifically, after the exhaustive search technique is performed at the base layer, the candidate Modes for enhancement layers can be reduced to a small number based on the correlation. Experimental results show that the fast Mode Decision scheme reduces the computational complexity significantly with negligible coding loss and bit-rate increases
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fast Mode Decision for spatial scalable video coding
International Symposium on Circuits and Systems, 2006Co-Authors: Changyun Wen, Lappui ChauAbstract:Scalable video coding (SVC) is an on-going standard and the current working draft (WD) is an extension of H.264/AVC. It provides scalability at the bit stream level with good compression efficiency, and allowing free combinations of spatial, temporal and SNR scalability. In the WD, exhaustive search technique is employed to select the best coding Mode for each macroblock. This technique achieves highest possible coding efficiency, but it results in higher computational complexity. To overcome this, we propose a novel fast Mode Decision scheme for spatial scalability in SVC. In this scheme, the Mode distribution relationship between base layer and enhancement layers is employed to reduce the candidate Mode set at enhancement layers. The experimental results show that the proposed scheme provides significant reduction in computational complexity without any noticeable coding loss.
F Pan - One of the best experts on this subject based on the ideXlab platform.
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fast Mode Decision algorithm for intraprediction in h 264 avc video coding
IEEE Transactions on Circuits and Systems for Video Technology, 2005Co-Authors: F Pan, Xiao Lin, Susanto Rahardja, K P LimAbstract:The H.264/AVC video coding standard aims to enable significantly improved compression performance compared to all existing video coding standards. In order to achieve this, a robust rate-distortion optimization (RDO) technique is employed to select the best coding Mode and reference frame for each macroblock. As a result, the complexity and computation load increase drastically. This paper presents a fast Mode Decision algorithm for H.264/AVC intraprediction based on local edge information. Prior to intraprediction, an edge map is created and a local edge direction histogram is then established for each subblock. Based on the distribution of the edge direction histogram, only a small part of intraprediction Modes are chosen for RDO calculation. Experimental results show that the fast intraprediction Mode Decision scheme increases the speed of intracoding significantly with negligible loss of peak signal-to-noise ratio.
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fast intra Mode Decision algorithm for h 264 avc video coding
International Conference on Image Processing, 2004Co-Authors: F Pan, L S Rahardja, K P Lim, Ce Zhu, Z LiangAbstract:The emerging H.264-AVC video coding standard aims to significantly improve compression performance compared to all existing video coding standards. In order to achieve this, a robust rate-distortion optimization (RDO) technique is employed to select the best coding Mode and reference frame for each macroblock. As a result, the complexity and computation load increase drastically. This paper presents a fast Mode Decision algorithm for H.264 intra prediction based on local edge information. Prior to intra prediction, an edge map is created and a local edge direction histogram is then established for each sub-block. Based on the distribution of the edge direction histogram, only a small part of intra prediction Modes are chosen for RDO calculation. Experimental results show that the last intra Mode Decision scheme increases the speed of intra coding significantly with negligible loss of PSNR.
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a directional field based fast intra Mode Decision algorithm for h 264 video coding
International Conference on Multimedia and Expo, 2004Co-Authors: F Pan, Xiao Lin, Susanto Rahardja, K P LimAbstract:The H.264 video coding standard can achieve considerably higher coding efficiency than previous standards. In order to achieve this, a robust rate-distortion optimization (RDO) technique is employed to select the best coding Mode for each macroblock. As a result. the encoder complexity is increased considerably. This paper presents a directional field based fast intra Mode Decision algorithm to improve the encoder's efficiency. Prior to intra prediction, the directional field is calculated for all the block size to decide the dominant edge direction in the blocks. Based on the edge direction information, only a small number of prediction Modes are chosen for RDO calculation. Experimental results show that the fast intra Mode Decision algorithm increases the speed of intra coding significantly with negligible loss of PSNR