将RGB图像转换为索引图像，包括图像矩阵和颜色图数组-The RGB image is converted into an index image, including image matrix and color map array

将彩色图像变为索引图像，程序有三行，而且包括抖动和非抖动，希望有人需要-Color image into indexed images, the program has three lines, and jitter and non-jitter, hoping that someone needs