一种快速分形图像编码算法

目前,分形图像编码技术最主要的缺点仍然是编码时间太长.因此,如何提高分形图像编码速度成为当前分形图像编码技术的研究热点.本文从分形图像编码通用公式推导出一个不等式,利用此不等式,可以预先排除大量不可能与值域块匹配的定义域块,从而减少值域块与定义域块的匹配计算,以此达到缩短编码时间的目的.实验结果表明,在解码图像质量基本不变情况下,本文的方法所使用的编码时间比Fisher方案所需的编码时间减少了很多.     

基于分形理论的图像压缩编码技术

分形图像压缩编码是当今图像编码领域研究的热点之一，是一种具有独特优势且极有发展前途的数据压缩技术。本文从分形基本理论出发，对分形图像压缩编码思想、编码方法等进行了综述，并介绍了分形图像压缩编码的一些改进方法。最后，探讨了分形图像压缩编码的发展方向。     

一种新的小波分形变换图像编码算法

提出了一种基于平滑双正交小波和自适应分割算法的小波域分形图像编码算法，在基于离散有限方差(DFV)最优准则下得到了适合图像编码的一种新的平滑双正交小波，从而改善了分块效应。在小波域的分形编码中，提出了一种基于图像信息分布特征的自适应分割算法，实验表明，该文算法在相同压缩比的情况下，解码图像的主观视觉质量和峰值信噪比都明显优于SQS方法、基本分形图像编码方法和SPIHT方法。     

分形与图像压缩编码

本文概述分形图像压缩的理论基础,介绍分形图像编码的IFS方法,讨论小波技术在分形图像编码中的应用。     

余域中分形方块编码的一种快速解码结构

分形方块编码（ＦＢＣ）作为一种具有高压缩比潜力的图像编码方法，正受到越来越多的关注，余域中的分形方块编码（ＦＢＣＲＤ）是对基本ＦＢＣ的一种改进，它使得在编码效应及恢复图像质量基本不变的情况下，解码的迭代次数和计算时间大为减少，本文针对ＦＢＣＲＤ又提出一种快速解码迭代结构，使得解码迭代过程进一步优化，实验表明，总的解码计算时间比基本的ＦＢＣ和非快速解码结构的ＦＢＣＲＤ都大大地减少了，这为分形图像编码     

小波与分形在图像压缩中的比较及应用

小波与分形都是当今图像编码领域中的热点。综述了小波和分形的原理、优缺点以及发展现状，并提出了基于小波和分形混合编码的思想。     

基于近距自相似模型的分形图像编码方法

为了克服分形图像编码方法速度低的弱点，提出了根据图像模型研究相应算法的思想。基于ρ｜ｒ｜图像模型，导出了与之相应的近距自相似模型，提供了一种适合于该模型的分形图像编码方法。实验结果表明，这种方法大大提高了编码速度，而且能有效地压缩图像数据     

改善分形图像编码视觉效果的有效方法研究

针对当前分形图像编码面临如何改善重建图像视觉效果的问题,利用局部图像的特点,采取自适应的分块方法与缩短编码时间的多种块分类技术相结合设计图像编码算法,该算法明显改善了图像编码视觉效果,编码时间缩短上千倍,具有快速实现分形图像编码之功效。     

分形图像编码的原理及其发展趋势

介绍了分形图像编码的原理及分形图像压缩的编码方法，提出了分形图像压缩编码的改进方法及其发展趋势。     

分形图像编码研究的进展

 分形图像编码是近几年发展起来的一种新的图像编码方法,目前对其研究较为广泛.本文介绍了分形图像压缩编码的数学原理、基本特性,着重介绍了当今这一领域的发展成果,比较了各种方案的优缺点,分析了目前编码方案所存在的缺点、原因及未来的发展方向.     

基于方向性零树小波的分形图像编码

该文阐述了分形图像方块编码在小波变换域内实现的原理,将零树概念扩展后与小波域的分形仿射变换相结合,提出一种基于方向性零树小波的分形图像编码方法。计算机模拟实验表明,在高压缩比时,其编码性能优于典型的基于四叉树分割的分形图像编码性能,接近于嵌入式零树小波编码(EZW)的性能。     

Prioritized DCT for compression and progressive transmission ofimages

An approach is based on the block discrete cosine transform (DCT). The novelty of this approach is that the transform coefficients of all image blocks are coded and transmitted in absolute magnitude order. The resulting ordered-by-magnitude transmission is accomplished without sacrificing coding efficiency by using partition priority coding. Coding and transmission are adaptive to the characteristics of each individual image. and therefore, very efficient. Another advantage of this approach is its high progression effectiveness. Since the largest transform coefficients that capture the most important characteristics of images are coded and transmitted first, this method is well suited for progressive image transmission. Further compression of the image-data is achieved by multiple distribution entropy coding, a technique based on arithmetic coding. Experiments show that the approach compares favorably with previously reported DCT and subband image codecs.     

引入非线性变换的分形图像压缩编码

提出了一种基于非线性变换的分形图像压缩编码方法。证明了引入的非线性变换满足压缩迭代映射理论。模拟实验的结果表明 ,与传统的分形图像压缩编码方法相比 ,压缩比和峰值信噪比均有所改善。     

基于矢量量化的层次分形编码方法

文中提出了一种新的分形图像压缩方法,该方法将矢量量化的概念应用于分形块编码中,对图像的平缓区进行矢量量化的线性组合编码,对图像的丰富细节区用分形编码,并且在分形编码时,采取了层次处理。实验表明,与基本的分形块编码方法相比,本文提出的矢量量化层次分形编码方法在保证一定的重建图像质量下,使图像的压缩比有了明显的提高,并且大大提高了编码和解码速度。     

基于方差不变特性的快速分形图像编码方法

本文结合图像子块的自身统计特性，提出一种基于方差不变特性的快速分形编码方法。实验结果表明，该方法可使编码速度有较大提高，而解码图像质量无明显下降；且有相对确定的编码时间，有助于编码系统的硬件实现。     

Image coding based on a fractal theory of iterated contractiveimage transformations

The author proposes an independent and novel approach to image coding, based on a fractal theory of iterated transformations. The main characteristics of this approach are that (i) it relies on the assumption that image redundancy can be efficiently exploited through self-transformability on a block-wise basis, and (ii) it approximates an original image by a fractal image. The author refers to the approach as fractal block coding. The coding-decoding system is based on the construction, for an original image to encode, of a specific image transformation-a fractal code-which, when iterated on any initial image, produces a sequence of images that converges to a fractal approximation of the original. It is shown how to design such a system for the coding of monochrome digital images at rates in the range of 0.5-1.0 b/pixel. The fractal block coder has performance comparable to state-of-the-art vector quantizers.     

Using Convex Set Techniques for Combined Pixel and Frequency Domain Coding of Time-Varying Images

Projection onto convex sets has recently been suggested as an approach to time-varying image compression. In this paper, an image coding technique based on such an approach is developed. In particular, pixel and frequency domain information is combined in order to improve image quality over standard transform coding at given bit rates. The use of nonintersecting convex sets is shown to be optimum for two sets and a given error measure. Convex sets and projections are discussed in general and then in the context of image compression. Simulation results are presented for single frame images as well as for image sequences.     

基于分级匹配和分形插值的图像压缩编码

本文在分形方块图像编码的基础上,提出一种分级匹配分形编码和分形插值相结合的图像压缩方法,实验结果表明,在基本保持重建图像质量的前提下,编码时间大为缩短。     

Image compression using binary space partitioning trees

For low bit-rate compression applications, segmentation-based coding methods provide, in general, high compression ratios when compared with traditional (e.g., transform and subband) coding approaches. In this paper, we present a new segmentation-based image coding method that divides the desired image using binary space partitioning (BSP). The BSP approach partitions the desired image recursively by arbitrarily oriented lines in a hierarchical manner. This recursive partitioning generates a binary tree, which is referred to as the BSP-tree representation of the desired image. The most critical aspect of the BSP-tree method is the criterion used to select the partitioning lines of the BSP tree representation, In previous works, we developed novel methods for selecting the BSP-tree lines, and showed that the BSP approach provides efficient segmentation of images. In this paper, we describe a hierarchical approach for coding the partitioning lines of the BSP-tree representation. We also show that the image signal within the different regions (resulting from the recursive partitioning) can be represented using low-order polynomials. Furthermore, we employ an optimum pruning algorithm to minimize the bit rate of the BSP tree representation (for a given budget constraint) while minimizing distortion. Simulation results and comparisons with other compression methods are also presented.     

基于DCT变换的渐进式图像编码方法

本文将DCT变换与SPECK算法相结合,提出了一种基于DCT变换的渐进式图像编码方法.该方法充分利用了DCT变换实现简单的特点,还能充分发挥零树编码的优势实现对图像的高效压缩.输出码流具有嵌入的特性,便于码率控制,具有一定的抗误码能力.同时计算复杂度低,比较适合于低复杂度的图像编码与传输.