android - android中的马赛克位图

Question

您好，我需要在 android 中制作马赛克效果。

转换这个:

对此:

我怎样才能做到这一点？谢谢

Answer 1

 /**
 * 效果能实现，但是是个耗时的操作
 *
 * @param bmp
 * @param precent 马赛克的程度（0-1）
 *                300*300 precent=1  time=57ms
 * @return
 */
public static Bitmap getMosaicsBitmap(Bitmap bmp, double precent) {
    long start = System.currentTimeMillis();
    int bmpW = bmp.getWidth();
    int bmpH = bmp.getHeight();
    Bitmap resultBmp = Bitmap.createBitmap(bmpW, bmpH, Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(resultBmp);
    Paint paint = new Paint();
    double unit;
    if (precent == 0) {
        unit = bmpW;
    } else {
        unit = 1 / precent;
    }
    double resultBmpW = bmpW / unit;
    double resultBmpH = bmpH / unit;
    for (int i = 0; i < resultBmpH; i++) {
        for (int j = 0; j < resultBmpW; j++) {
            int pickPointX = (int) (unit * (j + 0.5));
            int pickPointY = (int) (unit * (i + 0.5));
            int color;
            if (pickPointX >= bmpW || pickPointY >= bmpH) {
                color = bmp.getPixel(bmpW / 2, bmpH / 2);
            } else {
                color = bmp.getPixel(pickPointX, pickPointY);
            }
            paint.setColor(color);
            canvas.drawRect((int) (unit * j), (int) (unit * i), (int) (unit * (j + 1)), (int) (unit * (i + 1)), paint);
        }
    }
    canvas.setBitmap(null);
    long end = System.currentTimeMillis();
    Log.v(TAG, "DrawTime:" + (end - start));
    return resultBmp;
}

/**
 * 和上面的函数同样的功能，效率远高于上面
 *
 * @param bmp
 * @param precent
 * @return
 */
public static Bitmap getMosaicsBitmaps(Bitmap bmp, double precent) {
    long start = System.currentTimeMillis();
    int bmpW = bmp.getWidth();
    int bmpH = bmp.getHeight();
    int[] pixels = new int[bmpH * bmpW];
    bmp.getPixels(pixels, 0, bmpW, 0, 0, bmpW, bmpH);
    int raw = (int) (bmpW * precent);
    int unit;
    if (raw == 0) {
        unit = bmpW;
    } else {
        unit = bmpW / raw; //原来的unit*unit像素点合成一个，使用原左上角的值
    }
    if (unit >= bmpW || unit >= bmpH) {
        return getMosaicsBitmap(bmp, precent);
    }
    for (int i = 0; i < bmpH; ) {
        for (int j = 0; j < bmpW; ) {
            int leftTopPoint = i * bmpW + j;
            for (int k = 0; k < unit; k++) {
                for (int m = 0; m < unit; m++) {
                    int point = (i + k) * bmpW + (j + m);
                    if (point < pixels.length) {
                        pixels[point] = pixels[leftTopPoint];
                    }
                }
            }
            j += unit;
        }
        i += unit;
    }
    long end = System.currentTimeMillis();
    Log.v(TAG, "DrawTime:" + (end - start));
    return Bitmap.createBitmap(pixels, bmpW, bmpH, Bitmap.Config.ARGB_8888);
}

当你想将位图转换为马赛克位图时，调用函数即可

getMosaicsBitmaps(bmp,0.1)