opencv 实现图形填充，即将符合四连通或八连通定义的区域内的一点（常称为种子点）赋予给定颜色，然后将这种颜色扩展到整个区域的过程。-opencv graphics fill the area to be in line with the definition of four or eight connectivity connectivity point process (often referred to as seed points) giving a given color, this