Android播放器中我喜欢的一个地方-----高斯模糊效果

整个这个写的mp3中我最喜欢的就是这一点了，背景高斯模糊化。不废话，依旧看代码

package com.verzqli.utils;

import android.graphics.Bitmap;

/**
* Created by paveld on 3/6/14.
*/
public class FastBlur {

public static Bitmap doBlur(Bitmap sentBitmap, int radius, boolean canReuseInBitmap) {

// Stack Blur v1.0 from
// http://www.quasimondo.com/StackBlurForCanvas/StackBlurDemo.html //
// Java Author: Mario Klingemann <mario at quasimondo.com>
// http://incubator.quasimondo.com // created Feburary 29, 2004
// Android port : Yahel Bouaziz <yahel at kayenko.com>
// http://www.kayenko.com // ported april 5th, 2012

// This is a compromise between Gaussian Blur and Box blur
// 这是一个妥协于高斯模糊和方形模糊的产物
// It creates much better looking blurs than Box Blur, but is
// 他不但看上去的模糊效果比方形模糊更好，而且实现速度比高斯模糊要快
// 7x faster than my Gaussian Blur implementation.
// I called it Stack Blur because this describes best how this
// 我叫他堆栈模糊，因为他很好的阐述了过滤器是如何在内存中工作的。
// filter works internally: it creates a kind of moving stack
// of colors whilst scanning through the image. Thereby it
//  他实现了在移动颜色的栈的同时对图片进行扫描。
// just has to add one new block of color to the right side
// 其实它只是在栈的右边添加了一个新的颜色块，然后移除了最左边的颜色。
// of the stack and remove the leftmost color. The remaining
// 在栈最上层模块的剩余颜色块由他们所处的区域是属于栈右边还是左边来决定是增加还是删除
// colors on the topmost layer of the stack are either added on
// or reduced by one, depending on if they are on the right or
// on the left side of the stack.
//
// If you are using this algorithm in your code please add
// the following line:
// 如果你在你的代码中使用这个算法，请添加下面这行
// Stack Blur Algorithm by Mario Klingemann <mario@quasimondo.com>
// 堆栈模糊算法由Mario Klingemann <mario@quasimondo.com>所创作
// 翻译：verzqli，好吧，翻译的就像一坨(ˇˍˇ），英语好的自己理解下

Bitmap bitmap;
if (canReuseInBitmap) {
bitmap = sentBitmap;
} else {
//决定图片像素点的存储，即用图片查看器看图片属性时候的位深参数。
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];
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;
}
}

bitmap.setPixels(pix, 0, w, 0, 0, w, h);

return (bitmap);
}
}

原谅我，看了前面几行代码就不行了，后面的实在看不懂。我最开始是想用高斯模糊的，在renderScript（好像是这个吧）中，可是不知道是文件错误还是导入的时候问题，一直找不到某个方法，只好弃用了，然后后来我找到了这个方法，这个方法能实现高斯互摸效果的同时速度还能比它快，作者也是牛X。

//这下面一段是和背景模糊，你如果不用 就可以直接删掉，用一张你喜欢的图片替换即可，要用的话，后面的博客我再来讲
private void applyBlur() {
//这个方法我有点忘记了，你们可以百度下，貌似这样做是为了能够在onCreate中获取控件得尺寸，提前绘制出这个linearLayout。
linearLayout.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
@Override
public boolean onPreDraw() {
linearLayout.getViewTreeObserver().removeOnPreDrawListener(this);
linearLayout.buildDrawingCache(true);
linearLayout.buildDrawingCache();
Bitmap bitmap = MusicBitmap.getArtwork(MusicPlayActivity.this,
songList.get(songListPosition).getId(),
songList.get(songListPosition).getAlbumId(),
true, false);
if (bitmap != null) {
Bitmap bmp = bitmap;
blur(bmp, linearLayout);
} else {

Resources res = getResources();
Bitmap bmp = BitmapFactory.decodeResource(res, R.drawable.morenbg);
blur(bmp, linearLayout);
}

return true;

}

});
}

private void blur(Bitmap bkg, View view) {
//缩小倍数
float scaleFactor = 20;
//模糊程度，这个值越大，越模糊
float radius = 20;
//创建一个界面那么大的vbitmap
Bitmap overlay = Bitmap.createBitmap((int) (view.getMeasuredWidth() / scaleFactor),
(int) (view.getMeasuredHeight() / scaleFactor), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(overlay);
/**
* 这里作者用了一个奇特的思路，因为模糊一张大图片，很耗时间，搞不好还oom
* 所以他先将这个图片缩小了进行模糊，然后模糊完成之后，在放大到需要的地方，
* 速度又快，效果也不差
*/
canvas.translate(-view.getLeft() / scaleFactor, -view.getTop() / scaleFactor);
canvas.scale(1 / scaleFactor, 1 / scaleFactor);
Paint paint = new Paint();
//起到双缓冲作用，让时间变得更短，速度更快
paint.setFlags(Paint.FILTER_BITMAP_FLAG);
RectF rectF = new RectF(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());   //w和h分别是屏幕的宽和高，也就是你想让图片显示的宽和高
canvas.drawBitmap(bkg, null, rectF, null);
overlay = FastBlur.doBlur(overlay, (int) radius, true);
linearLayout.setBackgroundDrawable(new BitmapDrawable(getResources(), overlay));
}

上面一段是我对这个模糊效果的用法，如果你们想用的和我不一样，可以百度找到，我本来想上我原来看的那篇文章，可惜我没找到了，你们自己去寻找一下吧，当初我为了这个效果也是找了好久。

对了，最后发个效果图，原来的照片我删了，到[这里]看。(/article/8182153.html)