利用matlab将输入的rgb图像转化为灰度图像后，利用阈值求的二值图像，边缘算子求的边缘图像，边缘图像求归一化不变矩，Hu矩。-Matlab input rgb image to grayscale image, using the binary image threshold seeking child seeking the edge of the image, the edge operator, the edge of the image seeking normalized inva