我希望将模糊动画添加到 ImageView，但要设置持续时间。因此，例如，我希望图像随着时间的推移而模糊。

我已经有了模糊图像的方法，但我需要的是让它在 2 秒内从模糊变为无模糊。

谁能帮帮我？

编辑:这是我目前必须模糊图像的方法。

public Bitmap blur(Bitmap sentBitmap, int radius) {

    // Stack Blur Algorithm by Mario Klingemann <mario@quasimondo.com>

    Bitmap bitmap = sentBitmap.copy(sentBitmap.getConfig(), true);

    if (radius < 1) {
        return (null);
    }

    int w = bitmap.getWidth();
    int h = bitmap.getHeight();

    int[] pix = new int[w * h];
    Log.e("pix", w + " " + h + " " + pix.length);
    bitmap.getPixels(pix, 0, w, 0, 0, w, h);

    int wm = w - 1;
    int hm = h - 1;
    int wh = w * h;
    int div = radius + radius + 1;

    int r[] = new int[wh];
    int g[] = new int[wh];
    int b[] = new int[wh];
    int rsum, gsum, bsum, x, y, i, p, yp, yi, yw;
    int vmin[] = new int[Math.max(w, h)];

    int divsum = (div + 1) >> 1;
    divsum *= divsum;
    int dv[] = new int[256 * divsum];
    for (i = 0; i < 256 * divsum; i++) {
        dv[i] = (i / divsum);
    }

    yw = yi = 0;

    int[][] stack = new int[div][3];
    int stackpointer;
    int stackstart;
    int[] sir;
    int rbs;
    int r1 = radius + 1;
    int routsum, goutsum, boutsum;
    int rinsum, ginsum, binsum;

    for (y = 0; y < h; y++) {
        rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
        for (i = -radius; i <= radius; i++) {
            p = pix[yi + Math.min(wm, Math.max(i, 0))];
            sir = stack[i + radius];
            sir[0] = (p & 0xff0000) >> 16;
            sir[1] = (p & 0x00ff00) >> 8;
            sir[2] = (p & 0x0000ff);
            rbs = r1 - Math.abs(i);
            rsum += sir[0] * rbs;
            gsum += sir[1] * rbs;
            bsum += sir[2] * rbs;
            if (i > 0) {
                rinsum += sir[0];
                ginsum += sir[1];
                binsum += sir[2];
            } else {
                routsum += sir[0];
                goutsum += sir[1];
                boutsum += sir[2];
            }
        }
        stackpointer = radius;

        for (x = 0; x < w; x++) {

            r[yi] = dv[rsum];
            g[yi] = dv[gsum];
            b[yi] = dv[bsum];

            rsum -= routsum;
            gsum -= goutsum;
            bsum -= boutsum;

            stackstart = stackpointer - radius + div;
            sir = stack[stackstart % div];

            routsum -= sir[0];
            goutsum -= sir[1];
            boutsum -= sir[2];

            if (y == 0) {
                vmin[x] = Math.min(x + radius + 1, wm);
            }
            p = pix[yw + vmin[x]];

            sir[0] = (p & 0xff0000) >> 16;
            sir[1] = (p & 0x00ff00) >> 8;
            sir[2] = (p & 0x0000ff);

            rinsum += sir[0];
            ginsum += sir[1];
            binsum += sir[2];

            rsum += rinsum;
            gsum += ginsum;
            bsum += binsum;

            stackpointer = (stackpointer + 1) % div;
            sir = stack[(stackpointer) % div];

            routsum += sir[0];
            goutsum += sir[1];
            boutsum += sir[2];

            rinsum -= sir[0];
            ginsum -= sir[1];
            binsum -= sir[2];

            yi++;
        }
        yw += w;
    }
    for (x = 0; x < w; x++) {
        rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
        yp = -radius * w;
        for (i = -radius; i <= radius; i++) {
            yi = Math.max(0, yp) + x;

            sir = stack[i + radius];

            sir[0] = r[yi];
            sir[1] = g[yi];
            sir[2] = b[yi];

            rbs = r1 - Math.abs(i);

            rsum += r[yi] * rbs;
            gsum += g[yi] * rbs;
            bsum += b[yi] * rbs;

            if (i > 0) {
                rinsum += sir[0];
                ginsum += sir[1];
                binsum += sir[2];
            } else {
                routsum += sir[0];
                goutsum += sir[1];
                boutsum += sir[2];
            }

            if (i < hm) {
                yp += w;
            }
        }
        yi = x;
        stackpointer = radius;
        for (y = 0; y < h; y++) {
            // Preserve alpha channel: ( 0xff000000 & pix[yi] )
            pix[yi] = ( 0xff000000 & pix[yi] ) | ( dv[rsum] << 16 ) | ( dv[gsum] << 8 ) | dv[bsum];

            rsum -= routsum;
            gsum -= goutsum;
            bsum -= boutsum;

            stackstart = stackpointer - radius + div;
            sir = stack[stackstart % div];

            routsum -= sir[0];
            goutsum -= sir[1];
            boutsum -= sir[2];

            if (x == 0) {
                vmin[y] = Math.min(y + r1, hm) * w;
            }
            p = x + vmin[y];

            sir[0] = r[p];
            sir[1] = g[p];
            sir[2] = b[p];

            rinsum += sir[0];
            ginsum += sir[1];
            binsum += sir[2];

            rsum += rinsum;
            gsum += ginsum;
            bsum += binsum;

            stackpointer = (stackpointer + 1) % div;
            sir = stack[stackpointer];

            routsum += sir[0];
            goutsum += sir[1];
            boutsum += sir[2];

            rinsum -= sir[0];
            ginsum -= sir[1];
            binsum -= sir[2];

            yi += w;
        }
    }

    Log.e("pix", w + " " + h + " " + pix.length);
    bitmap.setPixels(pix, 0, w, 0, 0, w, h);

    return (bitmap);
}

最佳答案

模糊效果在 Android 上总是很困难。本质上，您必须在外观和性能之间做出决定。模糊看起来越好，花费的时间就越长，如果模糊本身不是瞬时的，那么您就无法真正为模糊设置动画。

你原来的模糊算法产生了非常好的结果，但正因为如此它也很慢使得模糊动画不可能。为了演示如何有效地模糊此图像，我通过缩小位图创建了一个简单的模糊动画:

public class BlurAnimation extends Animation {

    private final ImageView imageView;
    private final Bitmap bitmap;
    private final float startValue;
    private final float stopValue;
    private final float difValue;

    private BlurAnimation(ImageView imageView, Bitmap bitmap, int startValue, int stopValue) {
        this.imageView = imageView;
        this.bitmap = bitmap;
        this.startValue = startValue;
        this.stopValue = stopValue;
        this.difValue = stopValue - startValue;
    }

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        super.applyTransformation(interpolatedTime, t);

        int current = (int)(this.difValue * interpolatedTime + this.startValue + 0.5f);
        Bitmap blurred = quickBlur(this.bitmap, current);
        this.imageView.setImageBitmap(blurred);
    }

    public Bitmap quickBlur(Bitmap bitmap, int factor) {
        if(factor <= 0) {
            return Bitmap.createBitmap(1, 1, Bitmap.Config.ARGB_8888);
        }
        return Bitmap.createScaledBitmap(bitmap, bitmap.getWidth() / factor, bitmap.getHeight() / factor, true);
    }
}

这工作得很好(即使仍然有一些滞后)，但结果无法与您的模糊算法进行比较，它看起来很糟糕:

所以你看，在模糊图像时很难将性能和美观结合起来，但首先有一些选项 RenderScript。 RenderScript 速度非常快，并且具有内置的高斯模糊滤镜。我从未使用过它，但据我所知，它可能是您问题的解决方案。

您也可以尝试加载已经缩小的图像版本，这将产生与上面的 gif 相同的效果，但会更快。缺点是在 Animation 中使用它会再次出现问题，但如果您只需要模糊图像而不真正关心质量，那么您应该选择此选项。

您可以找到有关 RenderScript 和其他快速模糊选项的更多信息 in this answer

关于Android ImageView模糊动画，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/24826057/