说明：  灰度图像最小误差阈值分割法的二维推广灰度图像最小误差阈值分割法的二维推广灰度图像最小误差阈值分割法的二维推广
(Grayscale image minimum error thresholding method to promote two-dimensional gray-scale image minimum error thresholding method to promote two-dimensional gray-scale image minimum error thresholding method of two-dimensional extension)