摘要
图像编码标准以变换编码为核心,主要有离散余弦变换(DCT)和离散小波变换(DWT)两种。JPEG、MPEG和H.26系列大多采用DCT变换,基于DWT变换可进行多分辨率分析等优点,JPEG2000和MPEG.4等标准采用DWT变换。对图像进行变换编码得到的不同信息对于恢复原始图像信息的重要性是不同的。分级保护LT码通过改进每个节点的度为1和2的数据包的原始数据包的选择来提高对重要信息的纠错能力,非常适合应用于图像编码传输系统。
Transform coding is the core of image coding standards,mainly includes discrete cosine transform(DCT) and discrete wavelet transform(DWT). JPEG, MPEG and H.26 series use DCT transform for their advantages of DWT transform being able to do multi-resolution analysis. The JPEG2000 and MPEG.4 standard uses DWT transform. Different information obtained by transform coding on the images differs in importance to restore the original image information. Prioritized LT code improves the ability to select the original data packet of the data packet of node degree of 1 and 2 in order to improve the performance of the error correcting ability of important information, very suitable for image coding and transmission system.
出处
《电脑知识与技术（过刊）》
2014年第7X期4872-4874,4889,共4页
Computer Knowledge and Technology
基金
自然科学基金项目(61032003
61271172)
高等学校博士学科点专项科研基金(20120185110030
20130185130002)
四川省国际合作研究项目(2013HH0005)联合资助
