Pixelate Algorithm

Pixelate.java

public class PixelateUtil {
    /**
     * 普通图像－>像素图，zoneWidth为像素图的大像素的宽度
     */
    public static Bitmap pixelate(Bitmap bitmap, int zoneWidth) {
        return pixelate(bitmap, zoneWidth, 0, 0, bitmap.getWidth(), bitmap.getHeight());
    }

    /**
     * 普通图－>像素图，left、top、right、bottom可指定打马赛克区域
     */
    public static Bitmap pixelate(Bitmap bitmap, int zoneWidth, int left, int top, int right, int bottom) {
        int w = bitmap.getWidth();
        int h = bitmap.getHeight();
        Bitmap result = bitmap.copy(Bitmap.Config.ARGB_8888, true);
        Canvas canvas = new Canvas(result);
        Paint paint = new Paint();
        for (int i = left; i < right; i += zoneWidth) {
            for (int j = top; j < bottom; j += zoneWidth) {
                int color = bitmap.getPixel(i, j);
                paint.setColor(color);
                int gridRight = Math.min(w, i + zoneWidth);
                int gridBottom = Math.min(h, j + zoneWidth);
                canvas.drawRect(i, j, gridRight, gridBottom, paint);
            }
        }
        return result;
    }
}