此代码主要介绍了图像的稀疏映射，通过一副图像的四个点来确定映射函数，从而达到图像的映射，代码完整的解释了映射的详细算法-This code describes the mapping of the sparse image through an image four points to determine the mapping function, so as to achieve the image mapping, code complete a detailed explanation of the mapping algorithm! !