中文摘要：

研究了基于对角优先的矩形子模式搜索策略,即在矩形子模式的扫描过程中首先令横坐标和纵坐标不断同时加1,直到其为非同类块为止;然后再令横坐标（或纵坐标）不断增加,直到其再次为非同类块时停止搜索.通过使用扩展的Gouraud阴影法和对角优先的子模式搜索策略,提出了一种基于Gouraud阴影法和对角优先的RNAM（矩形非对称逆布局的模式表示模型）的图像表示方法（简称为DRNAMC表示方法）.标准灰度图像作为典型测试对象,实验结果表明：与流行的STC灰度图像表示方法相比,在保持图像质量的前提下,DRNAMC表示方法具有更高的压缩比和更少的块数.

英文摘要：

Diagonal-first strategy for searching a rectangle subpattern was studied.By using the extended Gouraud shading approach and the diagonal-first search strategy,a rectangular non-symmetry and anti-packing pattern representation model（RNAM） image representation method was proposed,which was called diagonal-first RNAM coding（DRNAMC） method.By taking some idiomatic standard gray images in the field of image processing as typical test objects,and by comparing the proposed DRNAMC method with the popular S-tree coding（STC） method,the experimental results show that the former has the higher compression ratio and the less number of blocks than the latter whereas maintaining the image quality,and therefore it is a better method to represent the gray image.