说明：  本程序主要完成pic到tif图像格式的转换（由图象格式转换菜单实现），并且完成了读写pic,tif图像文件的源代码。File/open挖图菜单完成在原始图中获取任意位置和大小的图像。
(This procedure to complete the main pic to tif image format conversion (from the image format conversion to achieve the menu), and completed the reading and writing pic, tif image files of the source code. File/open menu digging plans to complete in the original plan to obtain the location and size of arbitrary images.)