Dominant edge direction based fast intra mode decision in the H.264/AVC encoder

The H.264/AVC video coding standard uses an intra prediction mode with 4×4 and 16×16 blocks for luma and 8×8 blocks for chroma. This standard uses the rate distortion optimization （RDO） method to determine the best coding mode based on the compression performance and video quality. This method offers a large improvement in coding efficiency compared to other compression standards, but the computational complexity is greater due to the various intra prediction modes. This paper proposes a fast intra mode decision algorithm for real-time encoding of H.264/AVC based on the dominant edge direction （DED）. The DED is extracted using pixel value summation and subtraction in the horizontal and vertical directions. By using the DED, three modes instead of nine are chosen for RDO calculation to decide on the best mode in the 4×4 luma block. For the 16×16 luma and the 8 × 8 chroma, only two modes are chosen instead of four. Experimental results show that the entire encoding time saving of the proposed algorithm is about 67% compared to the full intra search method with negligible loss of quality.     

Improved fast inra prediction algorithm of H.264/AVC

With advanced prediction modes of intra prediction, intra coding of H.264/AVC offers significant coding gains compared with previous video coding standards. It uses an important tool called Lagrangian rate-distortion optimization (RDO) technique to decide the best coding mode for a block, but the computational burden is extremely high. In this paper, we proposed an improved fast intra prediction algorithm including block type selection and mode decision algorithm based on analysis of edge feature of a block. Our algorithm filters out unlikely block type and candidate modes to reduce the RDO calculations. Experimental results showed that the proposed algorithm can reduce the computation complexity of intra prediction from 52.90% to 56.31%, with 0.04 dB PSNR degradation and 2% increase of bit rate.     

一个改进的算术编码算法

Arithmetic coding is the most powerful technique for statiscal lossless encoding that has attracted much attention in recentyears. In this paper, we presents a new implementation of bit-level arithmetic coding by use of integer additions and shifts. The newalgorithm has less computation complexity and is more flexible to use, and thus is very suitable for software and hardware design. Wealso discuss the application of the algorithm to the data encryption.     

Color compensation for multi-view video coding based on diversity of cameras

A novel color compensation method for multi-view video coding （MVC） is proposed, which efficiently exploits the inter-view dependencies between views with the existence of color mismatch caused by the diversity of cameras. A color compensation model is developed in RGB channels and then extended to YCbCr channels for practical use. A modified inter-view reference picture is constructed based on the color compensation model, which is more similar to the coding picture than the original inter-view reference picture. Moreover, the color compensation factors can be derived in both encoder and decoder, therefore no additional data need to be transmitted to the decoder. The experimental results show that the proposed method improves the coding efficiency of M VC and maintains good subjective quality.     

A high fidelity VQ coding algorithm with region adaptive subbanding

Image subbands can be obtained by using filterbank. Traditional compression method uses direct entropy coding for each subband. After studying the energy distribution in image subbands, we proposed a vector quantization (VQ) coding algorithm to image subband. In the algorithm, vector quantizers were adaptively designed for high-frequency bands in an image. In particular, the edges of the image were examined and fewer bits were assigned to high-energy regions. The experimental result showe…     

A code-based approach for labeling in complex irregular regions

Labeling information in a complex irregular region is a useful procedure occurring frequently in sheet metal and the furniture industry which will be beneficial in parts management. A fast code-based labeler （FCBL） is proposed to accomplish this objective in this paper. The region is first discretized, and then encoded by the Freeman encoding technique for providing the 2D regional information by 1D codes with redundancies omitted. We enhance the encoding scheme to make it more suitable for our complex problem. Based on the codes, searching algorithms are designed and can be extended with customized constraints. In addition, by introducing a smart optimal direction estimation, the labeling speed and accuracy of FCBL are significantly improved. Experiments with a large range of real data gained from industrial factories demonstrate the stability and millisecond-level speed of FCBL. The proposed method has been integrated into a shipbuilding CAD system, and plays a very important role in ship parts labeling process.     

Dynamic performance analysis model of high-reliability EMS-Maglev system

In this paper, a modified transient finite element (FE) algorithm for the performance analysis of magnetically levitated vehicles of electromagnetic type is presented. The algorithm incorporates the external power system and vehicle’s movement equations into FE model of transient magnetic field computation directly. Sliding interface between stationary and moving region is used during the transient analysis. The periodic boundaries are implemented in an easy way to reduce the computation scale. It is proved that this method can be used for both electro-motional static and dynamic cases. The test of a transformer and an EMS-Maglev system reveals that the method generates reasonable results at very low computational costs comparing with the transient FE analysis.     

A fast motion estimation algorithm for mobile communications

The limitation of processing power, battery life and memory capacity of portable terminals requires reducing encoding complexity in mobile communications. Motion estimation (ME) is the most computationally intensive module in a typical video codec, which determines not only the encoder's performance but also the reconstructed video quality. In this paper, a fast ME algorithm for H.264/AVC baseline profile coding is proposed based on the analysis of motion vector field and error surface, and the statistical distributions of different type macroblocks (MBs). Simulation results showed that: in comparison with MVFAST, the proposed algorithm can decrease the computational load over 7.2% with no requirement of expanding memory capacity while maintaining the same video quality as MVFAST. Furthermore, its simplicity makes it easy to be implemented on hardware.     

A Fast Fractal Image Compression Coding Method

Fast algorithms for reducing encoding complexity of fractal image coding have recently been an important research topic.Serach of the bast matched domain block is the most computation intensive part of the fractal encoding process.In this paper,a fast fractal approximation coding scheme implemented on a personal computer based on matching in range block‘s neighbours is presented.Experimental results show that the proposed algorithm is very simple in implementation,fast in encoding time and high in compression ratio while PSNR is almost the same as compared with Barnsley‘s fractal block coding.     

Outlier Detection in Near Infra-Red Spectra with Self-Organizing Map

A new method to detect multiple outliers in multivariate data is proposed. It is a combination of minimum subsets, resampling and self-organizing map (SOM) algorithm introduced by Kohonen,which provides a robust way with neural network. In this method, the number and organization of the neurons are selected by the characteristics of the spectra, e. g., the spectra data are often changed linearly with the concentration of the components and are often measured repeatedly, etc. So the spatial distribution of the neurons can be arranged by this characteristic. With this method, all the outliers in the spectra can be detected, which cannot be solved by the traditional method, and the speed of computation is higher than that of the traditional neural network method. The results of the simulation and the experiment show that this method is simple, effective, intuitionistic and all the outliers in the spectra can be detected in a short time. It is useful when associated with the regression model in the near infra-red research.     

基于相邻帧相关性的帧间宏块模式选择算法

H．264／AVC在帧间运动估计／补偿编码过程中定义了7种帧间编码模式，并采用率失真优化全遍历策略来选择最优模式，这使计算复杂度急剧增加．针对这一问题，阐明了需对如何准确、快速地对块预测模式做出选择进行相关的研究．并就利用自然图像序列中相邻帧所表现出的强相关性提出了一种快速的帧间编码模式选择算法，通过计算部分编码模式来减少计算的复杂性．实验结果表明，该方法平均节省时间约18％，比特率平均下降约0．02％，而PSNR平均仅仅降低0．02dB．     

Edge Feature Based Fast Mode Decision Algorithm for H. 264 Intra Prediction

The emerging video coding standard H.264[1],provides the state-of-the-art video coding techniquesto meet a wide range of applications. Among thosetechniques, intra prediction is regarded as one of themain factors that contribute to the success ofH.264[2]. The rate distortion optimization (RDO)technology has been employed in H.264 for intra pre-diction mode selection to achieve good codingefficien-cy, which makes encoder extremely complex. Efforts have been made in developing fast H.264intra…     

基于TMS320DM6446的H.264视频编码器的实现及优化

文章为实现基于TMS320DM6446的H.264视频编码器的实时性能,提出一系列优化方法.首先描述X264代码向TMS320DM6446平台的移植过程,然后从项目级优化、指令级优化和算法级优化等几个方面提出优化实现方案.实验结果表明：对于CIF格式的视频,优化后的H.264编码器可以达到24帧/s以上的编码速度,基本满足视频监控系统中编码器的需求.     

Improved fast intra prediction algorithm of H.264/AVC

With advanced prediction modes of intra prediction, intra coding of H.264/AVC offers significant coding gains compared with previous video coding standards. It uses an important tool called Lagrangian rate-distortion optimization (RDO) technique to decide the best coding mode for a block, but the computational burden is extremely high. In this paper, we proposed an improved fast intra prediction algorithm including block type selection and mode decision algorithm based on analysis of edge feature of a block. Our algorithm filters out unlikely block type and candidate modes to reduce the RDO calculations. Experimental results showed that the proposed algorithm can reduce the computation complexity of intra prediction from 52.90% to 56.31%, with 0.04 dB PSNR degradation and 2% increase of bit rate.     

A fast motion estimation algorithm for mobile communications

The limitation of processing power, battery life and memory capacity of portable terminals requires reducing encoding complexity in mobile communications. Motion estimation (ME) is the most computationally intensive module in a typical video codec, which determines not only the encoder’s performance but also the reconstructed video quality. In this paper, a fast ME algorithm for H.264/AVC baseline profile coding is proposed based on the analysis of motion vector field and error surface, and the statistical distributions of different type macroblocks (MBs). Simulation results showed that: in comparison with MVFAST, the proposed algorithm can decrease the computational load over 7.2% with no requirement of expanding memory capacity while maintaining the same video quality as MVFAST. Furthermore, its simplicity makes it easy to be implemented on hardware.     

H.264视频编码器在DSP芯片的实现

H.264标准的提出满足日益增长的视频应用对运动图像更高的压缩性能的需要,极大地降低了发送视频图像所需要的带宽,适用于多样化的网络环境。采用TMS320DM642实现H.264编码器是一种快速有效的方法,具有多视频处理功能、接口丰富、算法灵活和可根据视频信号处理的特点进行优化等优点。本文主要论述了采用TMS320DM642芯片实现H.264视频编码器的硬件设计及在DSP/B IOS操作系统中实现H.264编码器的软件设计,本系统设计的编码器能够脱离计算机,实现CIF格式视频流的实时编码。     

Fast mode decision for inter macroblocks in H. 264/AVC

In this paper, a fast mode decision algorithm for inter macroblocks in H.264/AVC is proposed, The algorithm is able to classify all modes by both gradient operator and comparison of space-time correlation. Because only part of modes is used to compare with each other the computational complexity can be reduced greatly. The simulation results show that it takes about 75 % of encoding time for other algorithm with similar visual quality.     

基于H.264/AVC帧间宏块预测模式的快速判决方法

1 Introduction The emerging H.264/AVC video coding standard hasbeen developed and standardized collaboratively byboth ITU-T VCEG and ISO/IEC MPEG organizations .As the newest international video coding standard ,H.264/AVC represents a number of advances i…