说明：  注意： 1。tc支持16色，所以所读的图片要是16色图片 2。图片的的存放是从最后一行开始的，倒过来存放的 3。每行的字节数是4的倍数
(attention : 1. Tc support 16 colors, and read the picture if two 16-color pictures. Photo storage is the last line from the start, the reverse of the three storage. Each trip is the number of bytes in multiples of 4)