请问这段数字识别ImageProcess程序是什么意思

877 程序

[tr]不明白下面这段程序，哪位高抬贵手指点一二。大概的过程或者原理，都可以。跪谢。
//图像分割 (源图像, 区域数, 各个区域的起始结束坐标) 逐行像素扫描
void IMG_segmentation(const unsigned char *SourceImage, char *AreaNum, unsigned int *Coord)
{
      unsigned int x, y, i, j;
      unsigned char gray = 0, oldgray = 0;
      char line = 0;
      unsigned int updown[100];
      char num = 0;

      x = (SourceImage[2] << 8) + SourceImage[1]; //一行的像素数
      y = (SourceImage[4] << 8) + SourceImage[3]; //一列的像素数

      for(i=5; i       {
            for(j=5; j             {
                     GetPixelValue(SourceImage, j, i, &gray);
                     if(gray == 0)
                              break;
            }

            if((oldgray == 0xff) && (gray == 0))
            {
                     updown[line] = i; //y坐标上端
                     line++;
            }

            if((oldgray == 0) && (gray == 0xff))
            {
                     updown[line] = i; //y坐标下端
                     line++;
            }
            oldgray = gray;
      }

      for(; line>=0; line=line-2)
      {
            for(i=5; i             {
                     for(j=updown[line-2]; j                      {
                              GetPixelValue(SourceImage, i, j, &gray); //总在这个位置跑死，谁能帮帮我
                              if(gray == 0)
                                    break;
                     }

                     if((oldgray == 0xff) && (gray == 0))
                     {
                              Coord[num*4] = i; //区域的起始x坐标
                              Coord[num*4+1] = updown[line-2]; //区域的起始y坐标
                     }

                     if((oldgray == 0) && (gray == 0xff))
                     {
                              Coord[num*4+2] = i; //区域的结束x坐标
                              Coord[num*4+3] = updown[line-1]; //区域的结束y坐标
                              num++;
                     }
                     oldgray = gray;
            }
      }

      *AreaNum = num;
}

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