按边缘信息分类的图象变换编码

A Classified Trans-form Coding of Images Based on Image Edge Information

本文在分析图象边缘特征与视觉机理的基础上提出了一种新的自适应变换编码。该方法根据图象边缘控制信息在空间域对图象子块分类,然后在变换域依各类不同特征采取合适的抽样、量化和编码,特别是设计了适于平直边缘数据压缩的柱形滤波器。计算机模拟实验以标准人物头肩图象为例,其结果表明在码率0.2bit/pel时输出图象主观质量良好,峰峰信噪比约为33.9dB。

A new adaptive transform image coding, which is based on the analysis of features for image edges and brain mechanism of vision, is presented in this paper. The image sub-blocks are classified according to the control information of the image edges in spatial domain firstly, then resampling, quantizing and coding are realized according to different features of these classifications in transform domain, particularly some rectangle filters are de-signed suitable to data compression of the image sub-blocks which are part of the lines and directional edges in the image. Finally, the results of computer simulation with the example of a standard image of human head and shoulder are given. The experimental results show that the subjective quality of the coding image is good and the PSNR reaches 33.9dB when the code rate is as low as 0.2bit/pel.