【作者】 任崇广；

【导师】 张苗苗； 徐燕凌； 黄晓东；

【作者基本信息】 同济大学 ， 软件工程， 2008， 硕士

【摘要】 随着多媒体技术的广泛应用,图像压缩技术不仅需要较高的压缩性能,而且还要求有新的特性来满足一些特殊要求,JPEG2000标准便在此需求背景下被制定。JPEG2000是由联合图像专家组为静态图像编码所制定的一个新的国际标准。它不仅能提供优于现行标准的率失真特性和主观图像质量,且能提供现行标准不能有效或完全不支持的特性和功能。本文首先对JPEG2000及其所支持的感兴趣区域图像编码技术的研究背景和国内外研究现状经行了介绍,并对感兴趣区域提取方法进行了分析。其次深入研究了图像压缩技术的原理和主要算法,详细阐述了JPEG2000标准的框架结构。本文的重点是研究JPEG2000标准的感兴趣区域的提取以及其编码方法。对各种感兴趣区域的提取方法进行研究,提出了基于微分算子边缘检测的人机交互的感兴趣区域提取,并通过实验验证。JPEG2000标准定义了两种感兴趣区域编码算法:最大平移法(Maxshift Method)和一般平移法(Scaling-based Method)。最大平移法不允许任何背景区域(BG)比特面(bitplans)优先于感兴趣区域比特面进行编码;一般平移法只支持矩形和圆形两种形状ROI编码,而不能进行任意形状ROI编码。本文在此基础上分析了各种改进的感兴趣区域编码方法,并通过实验进行验证。并提出了基于黄金分割点的感兴趣区域编码方法,首先,通过基于微分算子的边缘检测进行人机交互的提取出感兴趣区域,通过产生ROI掩模和对ROI掩模内的系数按黄金分割点比例进行放大,使所定义的感兴趣区域有较好的压缩效果。实验表明此方法能够有效的对感兴趣区域进行编码,得到的图像有较高的质量。更多还原

【Abstract】 With the increasing use of multimedia technologies,image compression requires higher performance as well as new feature.The standard of JPEG2000 arises under such background.JPEG2000 is a new international standard approved by the Joint Photographic Experts Group for still image coding.It is not only intended to provide rate-distortion and subjective image quality performance superior to existing standards,but also to provide features and functionalities that current standards can not address efficiently and in many cases cannot address at all.The article first introduces the research background and the domestic and foreign research present situation of image compression code technology based on JPEG2000 at present,and analyses the extraction of regions of interest.Next research the principle and popular techniques of image compression,and analyses the frame-work of the JPEG2000.The research of ROI encoding and the extraction of ROI are mainly involved.I researched on methods of extraction of ROI,and proposed the extraction of ROI based on Differential operator and Human-Computer Interaction,then validated them by experiment.JPEG2000 supports two RO1 coding methods:the Maxshift method and the general scaling based method.The Maxshift method has the disadvantage of having to code all ROI regions prior to coding any part of the non-R01 region.On the other hand,the general scaling based method of JPEG2000 only supports rectangle and rotundity ROIs.The article researched on many improved algorithms base on this theory,and validated them by experiments.I proposed a method of image coding based on the golden section.First,extract ROI based on Differential operator and Human-Computer Interaction,produce the mask of ROI,and then magnify the coefficient based on the golden section.So the compression of ROI are better than background.The experimental results show that the method can code ROI excellent,and the quality of image is good.更多还原