初学者可往下看本例程的原理： 1、依次获得取样点的颜色 2、在取样点画该颜色的方框 取样越精，方框越小，图像就越清晰 -Beginners can look down the principles of this routine: 1, followed by access to the color of sampling points 2, stipple the colors in the sampling of the more refined sampling box,