基于混合色度采样率的全色度屏幕图像及视频编码研究

项目名称： 基于混合色度采样率的全色度屏幕图像及视频编码研究

项目编号： No.61201226

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 电子学与信息系统

项目作者： 王淑慧

作者单位： 同济大学

项目金额： 25万元

中文摘要： 随着"云计算"、"移动计算"等新型计算模式的出现，计算机屏幕图像编码成为视频编码领域的一个热门研究课题。屏幕图像由连续色调及非连续色调两种内容构成，分别适合采用不同的方法压缩。过去几十年视频压缩的软硬件技术开发都是针对色度子采样YUV420或YUV422视频。把屏幕图像色度子采样成YUV420或YUV422图像再编码会导致非连续色调内容的明显失真，必须对YUV444屏幕图像进行压缩。完全采用全色度编码（至少两个编码器，一个针对连续色调内容，另一个针对非连续色调内容）会带来巨大的人力、物力投入。本项目提出了混合色度采样率MCS的屏幕图像编码技术，通过不同色度采样率编码的混合策略、全色度无损编码、计算复杂度及码率控制等方面的研究，形成一套高压缩比、超高质量、极低复杂度的屏幕图像压缩的理论、算法及软件实现方案，最大限度降低开发成本，解决目前屏幕图像压缩算法难以满足高清屏幕实时传输的要求的难题。

中文关键词： 屏幕图像编码；混合编码；串匹配；混合色度采样率；仿二维匹配

英文摘要： In recent years, with the emergence of some new computing styles, such as "cloud computing", "cloud rendering", "mobile computing", etc., screen content coding attracts great attention of researchers from both academia and industry and becomes a hot topic in video coding filed. Computer screen content can be classified into two types: computer-generated discontinuous tone content and camera-captured continuous tone content. The two types of content can be compressed effectively by different tailored methods. The majority of video CODEC software, hardware developed in the past several decades are chroma-subsampled (YUV420 or YUV422 format) ones. Unfortunately, chroma subsampling of screen image significantly degrades the visual quality of discontinuous tone content. Thus, it is necessary to compress screen image with YUV444 format. Completely adopting full-chroma coders(at least two coders, one for continuous tone content and the other for discontinuous tone content) not only significantly increases the cost of human resources but also requires tremendous investment. Since quite some portions of a compound image are continuous tone content, coding the entire image using two full-chroma coders is a overkill and too expensive. This project proposes a Mixed Chroma Sampling-rate (MCS) coding technique that combines o

英文关键词： screen content coding；hybrid coding；string matching；Mixed Chroma Sampling-rate；Pseudo-2D-matching