将含多个目标的图像减去背景图，再将所得图进行阈值化处理得二值图像，再对二值图像进行标记，然后跟含多个目标的图像进行处理，对这个图像进行多目标标记-Containing a plurality of target image by subtracting a background image, and the resulting graph threshold processing binary image to be marked, then the binary image, and then processed with an image containing a plurality of target, this image multi-target mark