将一幅彩色图像二值化为灰度图像，其中灰度值大于某一阈值的像素赋予灰度值1，小于该阈值的像素赋予灰度值0-A color image to a grayscale image binarized, wherein the gray value is greater than a threshold value assigned to the pixel gray value 1, is smaller than the threshold value assigned to the pixel g