采用8种方法对图像Mat的像素进行扫描，并对像素点的像素进行压缩，压缩间隔为div=64,并比较扫描及压缩的效率,效率最高的是采用.ptr及减少循环次数来遍历图像，并采用位操作来对图像像素进行压缩。-8-Mat method for image scanning pixel pixel pixel compression and compression interval div = 64, and scanning and comparing the compression efficiency is the use of the highest efficiency. Ptr and the number of cycles to traverse image and compressed using bit operations on the image pixels.