Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 60 )

2018 ( 241 )

2017 ( 246 )

2016 ( 263 )

Custom range...

Search Results: 1 - 10 of 5199 matches for " intra-prediction "
All listed articles are free for downloading (OA Articles)
Page 1 /5199
Display every page Item
Quantization based Semi-fragile Watermarking Scheme for H.264 Video
Yong Zhang,Zhe-Ming Lu,Dong-Ning Zhao
Information Technology Journal , 2010,
Abstract: Although, many fragile video watermarking techniques have been proposed as an effective solution to content authentication problems, they cannot effectively distinguish between legal attacks and illegal attacks. In order to solve this problem, this paper proposes a novel semi-fragile video watermarking algorithm for H.264 video. Traditional fragile video watermarking methods often select the motion vectors as the embedding positions, while our scheme adopt the intra-prediction residuals after Integer DCT (Discrete Cosine Transform) and quantization to be embedding locations. During the watermark embedding process, we modify the standard H.264 quantizer and we embed the watermark based on the dither modulation technique in order to extract the watermark blindly. In the watermark extraction process, this paper adopts a threshold to distinguish between illegal attacks and legal attacks performed on the video clip. Experimental results demonstrate the effectiveness and feasibility of the proposed algorithm and the proposed scheme can survive legal recompression operations and recognize illegal filtering operations.
Fast Intra-prediction Mode Selection Algorithm for H. 264

ZHANG Jiang-xin,FENG Ming,

中国图象图形学报 , 2008,
Abstract: H.264 introduces intra-prediction coding technique to improve the intra-coding efficiency.This enormously increases the computational complexity. In order to decrease the computational complexity of the algorithm,a fast algorithm for intra-prediction mode decision based on pixel's edge vector's variance,the relation between sub-block's mode and macro-block's mode. Experimental results show that compared with the original intra-prediction coding scheme,the proposed algorithm reduce the computational complexity of intra-prediction coding dramatically with only trivial loss of PSNR and increment of bite-rate.
A Fast Intra-prediction Mode Selection Algorithm Based on H.264/AVC

XIAO Guang,XIAO Guang,XIAO Guang,

中国图象图形学报 , 2005,
Abstract: In H.264/AVC, intraprediction is used to improve the coding efficiency of I frame. There are one size of 8×8 for the chroma block and two sizes including 4×4 and 16×16 for the luma block. Each kind of block provides many prediction modes, so that this multimode selection increases the coding complexity greatly while improving coding efficiency. In this paper, a fast intraprediction mode selection algorithm with different criterion based on RDO(Rate distortion optimization) is proposed using the mode selection relation of chroma block and luma block and the relation of luma 4×4 block and luma 16×16 block. Experiment results show that our proposed algorithm can averagely speed up to times while maintaining similar PSNR and bit rate.
Fast intra-prediction mode selection algorithm for H.264/AVC

ZHANG Min,GENG Guo-hua,

计算机应用研究 , 2011,
Abstract: This paper proposed a fast prediction mode selection algorithm based on measurement of direction prediction mode, by measuring the intra-prediction direction of 4×4 block, it used the correlation between neighboring blocks and neighboring direction prediction mode to predict the intra-frame mode. Experimental results show that compared with the full searching algorithm, this algorithm can save the encoding time up to 40% averagely when guarantee the capability of the rate distortion and the bits rate, and it improves the encoding efficiency tremendously.
Fast intra prediction mode selection algorithm of H.264/AVC based on all-zero blocks detection

ZHOU Xin,DUAN Zhe-min,ZHOU Wei,

计算机应用研究 , 2011,
Abstract: The newly proposed video coding standard H.264/AVC can achieve much higher efficiency than previous standards with intra-frame prediction.Unfortunately this comes at a cost in greatly increased complexity at the encoder mainly due to motion estimation and intra prediction block mode decision.This paper proposed a fast intra prediction mode selection algorithm of H.264/AVC based on the all-zero blocks detection to optimize intra block mode decision to significantly improve the time efficiency of the encoder ...
A kind of high definition intra-prediction unit fast selection algorithm

福州大学学报(自然科学版) , 2016,
Abstract: 针对高效视频编码标准提出一种CU划分快速终止算法. 该算法选择图像纹理复杂度作为特征向量,将HEVC帧内预测与k-means聚类方法相结合,通过每种尺寸CU的聚类中心减少率失真优化的次数,提前终止CU块的划分,在达到降低编码复杂度的同时依然保持较好的编码效率. 测试结果表明,本算法与参考算法HM10.0相比较,视频图像质量基本不变,而编码时间大幅减少.
We proposed a CU fast selection algorithm for high efficiency video coding standard,we select the image texture complexity as the feature vector,combined the HEVC intra prediction with k-means clustering method,reduce times of the CU rate distortion optimization sizes and make early divided termination of CU blocks by each cluster centers,reduce coding complexity while still maintaining good coding efficiency. The test results show that the algorithm is compared with the reference algorithm HM10.0,video quality will remain basically unchanged,while significantly reducing encoding time
Fast DC Mode Prediction Scheme For Intra 4x4 Block In H.264/AVC Video Coding Standard
Tajdid UI Alam,Jafor Ikbal,Touhid Ul Alam
International Journal of Advanced Computer Sciences and Applications , 2012,
Abstract: In this paper, the researchers proposed a new scheme for DC mode prediction in intra frame for 4X4 block. In this scheme, the upper and left neighboring pixels would be used to predict each of the pixels in the 4X4 block with different weight. The prediction equations for each position of the 4X4 block in DC mode would be static with fixed weighting coefficients. As a result, the computational time for intra frame would be decreased considerably with an increase in PSNR.
A Multithreaded Implementation of HEVC Intra Prediction Algorithm for a Photovoltaic Monitoring System
Yungho Choi,Hyungkeun Ahn
Transactions on Electrical and Electronic Materials , 2012,
Abstract: Recently, many photovoltaic systems (PV systems) including solar parks and PV farms have been built to preparefor the post fossil fuel era. To investigate the degradation process of the PV systems and thus, efficiently operate PVsystems, there is a need to visually monitor PV systems in the range of infrared ray through the Internet. For efficientvisual monitoring, this paper explores a multithreaded implementation of a recently developed HEVC standard whosecompression efficiency is almost two times higher than H.264. For an efficient parallel implementation under a meshbased64 multicore system, this work takes into account various design choices which can solve potential problems ofa two-dimensional interconnects-based 64 multicore system. These problems may have not occurred in a small-scalemulticore system based on a simple bus network. Through extensive evaluation, this paper shows that, for an efficientmultithreaded implementation of HEVC intra prediction in a mesh-based multicore system, much effort needs to bemade to optimize communications among processing cores. Thus, this work provides three design choices regardingcommunications, i.e., main thread core location, cache home policy, and maximum coding unit size. These designchoices are shown to improve the overall parallel performance of the HEVC intra prediction algorithm by up to 42%,achieving a 7 times higher speed-up.
A Fast Mode Selection Algorithm Using Texture Analysis for H.264/AVC
Sourabh Rungta,Kshitij Verma,Vahid Majid Nezhad
International Journal of Computer Science Issues , 2010,
Abstract: H.264/AVC, the newest international video coding standard achieves higher compression efficiency as compared to all other existing coding standard such as MPEG-4 and H.263. However this efficiency comes with a dramatic increase in computational complexity due to several advanced techniques, such as inter mode and intra mode prediction with variable size motion compensation. It adopts rate distortion optimization (RDO), while maximizing visual quality and minimizing the required bit rate. In this paper, we propose a fast inter mode selection algorithm. The aim is to reduce the number of modes in intra and inter mode prediction. Experimental results show that this algorithm reduces the total encoding time with little loss of bit rate and visual quality.
On Fast Intra Prediction Mode Decision Algorithm for 4 × 4 Blocks in H. 264

HAN Qing,LI Li,YING Jun,

中国图象图形学报 , 2007,
Abstract: 在H.264视频编码过程中,编码时间受诸多因素的影响,如帧间/帧内模式选择、运动估计(ME)、率失真优化(RDO)等。为了以较快速度和较好质量进行编码,针对H.264帧内模式选择,提出了一种适用于H.264帧内4×4块预测的模式选择快速算法。该算法利用帧内4×4块最优预测模式与和它相邻的预测模式之间率失真代价(RDCost)的高相关性,以及绝对变换误差和(SATD)与率失真(RD)性能之间的强相关性,有效地跳过一些不太可能的预测模式,从而使帧内4×4块模式选择过程只需进行4次率失真代价计算即可。实验结果显示,该算法在编码性能和编码速度之间取得了很好的折衷。
Page 1 /5199
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.