说明：  一个完全解读PCX文件的自编程序，不使用任何调色板之类的高级函数，只使用极普通的文件读语句即OK。可以借鉴于认识PCX文件的本质结构。
(a complete explication PCX document written procedures, the use of any such palette High function, use only a very general statement read in the paper that is OK. We can draw on understanding the nature of PCX document structure.)