检索结果-内蒙古大学图书馆

image sequence coding USING QUADTREE-BASED BLOCK-MATCHING MOTION COMPENSATION AND CLASSIFIED VECTOR QUANTIZATION

IEE PROCEEDINGS-VISION image AND SIGNAL PROCESSING 1994年第6期141卷 453-460页

作者： LEE, MH CREBBIN, G Dept. of Electr. & Electron. Eng. Western Australia Univ. Nedlands Australia

The authors propose a new image sequence coding algorithm based on two crucial methods: quadtree segmentation and classified vector quantisation (CVQ). Overall coding rates are efficiently lowered by quadtree segmentation while visual quality is well preserved by a CVQ method. A moving-block extraction technique is employed to greatly improve the coding efficiency in the interframe coding mode. A quadtree efficiently segments the stationary background regions of interframe differential signals with various large-sized blocks, and the moving regions are extracted from the smallest blocks of 4 x 4 size during the growth of the quadtree. These moving regions are motion-compensated using a block-matching method based on 4 x 4 blocks and the residual signals of the motion-compensated moving regions are coded by CVQ. The stationary regions are simply replenished from the previous frame. The proposed coding scheme is effective for coding the sequential signals of video telephony or video conferencing at low bit rates.

关键词： CLASSIFIED VECTOR QUANTIZATION image sequence coding QUADTREE SEGMENTATION VIDEO TELEPHONY

来源：评论

学校读者我要写书评

暂无评论

CHANGE DETECTION AND TEXTURE ANALYSIS FOR image sequence coding

引用

SIGNAL PROCESSING-image COMMUNICATION 1994年第4期6卷 357-376页

作者： SIVAN, Z MALAH, D TECHNION ISRAEL INST TECHNOL DEPT ELECT ENGNIL-32000 HAIFAISRAEL

In Hybrid DPCM image sequence coders, every block with high variance in the corresponding difference block is replenished even if it belongs to a stationary background region, as could be the case for coarse textured blocks. We present an improved Hybrid DPCM image sequence coder, which includes a block classification suit. This unit detects stationary textured background blocks and allows copying such blocks instead of replenishing them, thus reducing the bit-rate of the coder. The unit consists of three parts. The first part is a statistical-based change detector. Segmentation of each image into textured and smooth regions, a fast converging deterministic relaxation procedure and a multi-resolution approach are used to obtain the final moving/stationary segmentation. In the second part, a Gaussian AR model-based texture matching test is proposed. The third part detects edges in stationary blocks. To avoid edge related artifacts, blocks that contain an edge are unconditionally coded. The coder which incorporates the proposed change detector was found, in simulations, to provide a substantial reduction in bit-rate, while maintaining the quality of the reconstructed sequences, in coding image sequences which contain large areas of coarse textured background.

关键词： image sequence coding VIDEO coding DPCM CHANGE DETECTION ICM MULTIRESOLUTION image SEGMENTATION TEXTURE EDGE DETECTION GIBBS DISTRIBUTION AR MODELING

来源：评论

学校读者我要写书评

暂无评论

A fast quadtree motion segmentation for image sequence coding

引用

SIGNAL PROCESSING-image COMMUNICATION 1999年第10期14卷 811-816页

作者： Salari, E Li, W Univ Toledo Dept Elect Engn & Comp Sci Toledo OH 43606 USA Thomson Consumer Elect Indianapolis IN 46206 USA

A new fast quadtree-based variable size block matching scheme is devised for image sequence coding. The novelty of the method lies in the quadtree-based block matching with significantly less computations. In the proposed method, the computational requirements for matching are largely transferred from the evaluation of the mean absolute difference to the computations of the sum norms of the blocks which can be easily obtained. The fast quadtree decomposition scheme partitions an image frame into uniform motion blocks (larger blocks) and non-uniform motion blocks (small blocks). Standard VQ-based interframe coding is applied to uniform motion blocks while non-uniform blocks are intraframe coded. Implementation of this method shows a significantly lower computational requirement and a good-quality reconstruction of images at low bit-rates. (C) 1999 Elsevier Science B.V. All rights reserved.

关键词： quadtree decomposition motion estimation vector quantization image sequence coding

来源：评论

学校读者我要写书评

暂无评论

Motion differential set partition coding for image sequence and video compression

引用

JOURNAL OF VISUAL COMMUNICATION AND image REPRESENTATION 2012年第4期23卷 634-641页

作者： Hu, Yang Pearlman, William A. Rensselaer Polytech Inst Dept Elect Comp & Syst Engn Troy NY 12180 USA

Efficient image sequence coding exploits both intra- and inter-frame correlations. Set partition coding (SPC) is efficient in intra-frame de-correlation for still images. Based on SPC, a novel image sequence coding system, called motion differential SPC (M-D-SPC), is presented in this paper. It removes inter-frame redundancy by re-using the significance map of a previously SPC coded frame. Every frame is encoded and decoded separate from other frames. Furthermore, there is no reconstruction of encoded frames in the encoder, as is done with interframe prediction methods. The M-D-SPC exhibits an auxiliary key frame coding framework, which achieves higher coding efficiency compared to the all-intra-coding schemes and meanwhile maintains the beneficial features of SPC all-intra-coding, such as computational simplicity, rate scalability, error non-propagation, and random frame access. SPIHT-based simulations on hyperspectral images, 3D/4D medical images, and video show greater compression efficiency than the standard intraframe coding method of motion JPEG2000. (c) 2012 Elsevier Inc. All rights reserved.

关键词： Video coding image sequence coding Motion coding Set partition coding Significance map SPIHT Random access Lossless coding

来源：评论

学校读者我要写书评

暂无评论

MOTION COMPENSATED sequence coding USING image PYRAMIDS

引用

ELECTRONICS LETTERS 1990年第9期26卷 575-576页

作者： WANG, Q CLARKE, RJ Heriott Watt Univ. Edinburgh UK

image coding using image pyramids is a technique originally developed for still pictures. The authors report an image sequence coding technique with motion compensation using image pyramids, which gives greater data c... 详细信息

关键词： compensation data compression data compression encoding image pyramids image sequence coding motion compensation picture processing picture processing

来源：评论

学校读者我要写书评

暂无评论

HIERARCHICAL image sequence MODEL FOR SEGMENTATION - APPLICATION TO REGION-BASED sequence coding

HIERARCHICAL IMAGE SEQUENCE MODEL FOR SEGMENTATION - APPLICA...

引用

Conference on Visual Communications and image Processing 94

作者： MARQUES, F VERA, V GASULL, A UPC ETSETBDEPT TEORIA SENAL & COMUNICACE-08080 BARCELONASPAIN

ISBN: (纸本)081941638X

This paper studies the performance of an image sequence model based on Compound Random Fields when used for segmentation purposes. The fact of using a hierarchical model allows characterizing separately the texture and contour information within the sequence. Moreover, temporal and spatial contour behavior can also be described independently. This separated characterization allows to impose constraints on the kind of contours to be obtained and to introduce some a priori knowledge in the segmentation procedure. The way to exploit these features for an object-based sequence coding scheme is analyzed. The influence of the model parameters on the segmentation results is analyzed, in order to achieve segmentations which can be easily coded. The main sought characteristics are smooth spatial contours, slow temporal variations and homogeneous textures. Two different segmentation algorithms are used for this analysis, a recursive and a nonrecursive one.

关键词： image sequence SEGMENTATION image sequence coding COMPOUND RANDOM FIELDS

来源：评论

学校读者我要写书评

暂无评论

image COMPRESSION BY GABOR EXPANSION

引用

OPTICAL ENGINEERING 1991年第7期30卷 873-880页

作者： EBRAHIMI, T KUNT, M Swiss Federal Institute of Technology (Switzerland) Swiss Federal Institute of Technology (Switzerland)

A compression technique based on a pyramidal expansion is presented. The elementary functions of the expansion form a class of pyramidal Gabor functions partitioning the frequency domain into different regions. Still images and moving image sequences are coded by selecting and quantizing the coefficients in this expansion. Computer simulation of the proposed method show good quality reconstruction of both still images and image sequences.

关键词： VISUAL COMMUNICATIONS image sequence coding GABOR FUNCTIONS GABOR TRANSFORMS MULTIRESOLUTION REPRESENTATION

来源：评论

学校读者我要写书评

暂无评论

A FULLY ADAPTIVE DCT BASED COLOR image sequence CODER

引用

SIGNAL PROCESSING-image COMMUNICATION 1994年第4期6卷 289-301页

作者： CHEN, RJ CHIEU, BC NATL TAIWAN INST TECHNOL DEPT ELECTR ENGNTAIPEI 10772TAIWAN

A new fully adaptive discrete cosine transform (DCT) based color image sequence coding system is presented. A variable size block matching motion-compensation scheme is first designed. It differs from the conventional block matching motion compensation by varying the block size to make a better trade-off between the required bit rate and picture quality. Connected to the compensation scheme is the DCT with block size varied adaptively to the working block size derived from the motion compensator. Different gating functions are defined on the DCT to select the most efficient DCT coefficients in order to reach the best performance. An adaptive Laplacian quantizer and a two-sided Huffman entropy coder are finally utilized to get the optimal coding result.

关键词： MOTION COMPENSATION image sequence coding QUADTREE-BASED VARIABLE SIZE BLOCK MATCHING image ACTIVITY ADAPTIVE ZONAL FILTERS ADAPTIVE LAPLACIAN QUANTIZER SCALING FACTOR 2-SIDED HUFFMAN CODE

来源：评论

学校读者我要写书评

暂无评论

MULTIPLEXING DIGITAL TELEVISION SOURCES ON ATM NETWORKS

引用

SIGNAL PROCESSING-image COMMUNICATION 1994年第5期6卷 435-462页

作者： LEDUC, JP IRISA/Centre INRIA Campus de Beaulieu Avenue du G&eacute n&eacute ral Leclerc F-35042 Rennes France

This paper investigates the transmission of digital television signals on ATM networks. The key characteristic of an ATM network is its ability of statistically multiplexing variable bit rate sources in queueing systems called multiplexers. These queues are optimally located at the output port of the switching fabrics and emptied at constant bit rate by the destined transmission links. In that framework, the paper intends to analyze the multiplexing of digital television sources which are connected at a given ATM node and share the same transmission resources. Consequently, the study starts with analyzing the packet traffic generated when pooling television sources. The paper proceeds with modeling the queue behaviours and, eventually, with deriving the multiplexing performances. These latter parameters refer to three main topics namely, the cell losses and their configurations, the transmission jitter and the statistical multiplexing. Both theoretical approaches and simulations are employed to yield the final performances. As an important issue, substantial multiplexing gains is also put into evidence through theoretical and experimental arguments. Cell loss configurations are presented to suggest what policy to implement for cell loss burst correction. It is further shown how random transmission delay and jitter turn out to be minor problems when dealing with the transmission of television services.

关键词： image sequence coding ATM NETWORKS STATISTICAL MULTIPLEXING

来源：评论

学校读者我要写书评

暂无评论

GLOBAL-MOTION ESTIMATION IN image sequenceS OF 3-D SCENES FOR coding APPLICATIONS

引用

SIGNAL PROCESSING-image COMMUNICATION 1995年第6期6卷 507-520页

作者： AMITAY, A MALAH, D TECHNION ISRAEL INST TECHNOL DEPT ELECT ENGNIL-32000 HAIFAISRAEL

A technique for global-motion estimation and compensation in image sequences of 3-D scenes is described in this paper. Each frame is segmented into regions whose motion can be described by a single set of parameters and a set of motion parameters is estimated for each segment. This is done using an iterative block-based image segmentation combined with the estimation of the parameters describing the global motion of each segment. The segmentation is done using a Gibbs-Markov model-based iterative technique for finding a local optimum solution to a maximum a posteriori probability (MAP) segmentation problem. The initial condition for this process is obtained by applying a Hough transform to the motion vectors of each block in the frame obtained by block matching. In each iteration, given a segmentation, the motion parameters are estimated using the least-squares (LS) technique. To obtain the final segmentation and the more appropriate higher-order motion model for each segment, a final stage of splitting/merging of segments is needed. This step is performed on the basis of maximum-likelihood decisions combined with the determination of the higher-order model parameters by LS. The incorporation of the proposed global-motion estimation technique in an image-sequence coder was found to bring about a substantial reduction in bit-rate without degrading the perceived quality or the PSNR.

关键词： image sequence coding VIDEO coding GLOBAL MOTION LOCAL MOTION HOUGH TRANSFORM LEAST SQUARES ICM MOTION ESTIMATION MOTION SEGMENTATION GIBBS DISTRIBUTION MAXIMUM LIKELIHOOD SPLITTING MERGING

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：