Android如何实现毛玻璃效果之Android高级模糊技术

非著名程序员

发布于 2018-02-01 16:21:48

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发布于 2018-02-01 16:21:48

文章被收录于专栏：非著名程序员

Android高级模糊技术

非著名程序员
自从iOS系统引入了Blur效果，也就是所谓的毛玻璃、模糊化效果，磨砂效果，各大系统就开始竞相模仿，这是怎样的一个效果呢，我们先来看一下，如下面的图片：

效果我们知道了，如何在Android中实现呢，说白了就是对图片进行模糊化处理，小编先给大家讲一下Android高级模糊技术的原理，如下： ·首先我创建了一个空的bitmap，把背景的一部分复制进去，之后我会对这个bitmap进行模糊处理并设置为TextView的背景。 ·通过这个bitmap保存Canvas的状态； ·在父布局文件中把Canvas移动到TextView的位置； ·把ImageView的内容绘到bitmap中； ·此时，我们就有了一个和TextView一样大小的bitmap，它包含了ImageView的一部分内容，也就是TextView背后一层布局的内容； ·创建一个Renderscript的实例； ·把bitmap复制一份到Renderscript需要的数据片中； ·创建Renderscript模糊处理的实例； ·设置输入，半径范围然后进行模糊处理； ·把处理后的结果复制回之前的bitmap中； ·好了，我们已经把bitmap惊醒模糊处理了，可以将它设置为TextView背景了；我最近在做一款App，其中有一个功能需要对图片处理实现毛玻璃的特效，经过一番研究，找到了3中实现方案，其中各有优缺点，如果系统的api在16以上，可以使用系统提供的方法直接处理图片，但是小编认为下边的解决方案是实现效果最好的。代码如下：

public Bitmap fastblur(Context context, Bitmap sentBitmap, int radius) {


 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];
 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 temp = 256 * divsum;
 int dv[] = new int[temp];
 for (i = 0; i < temp; 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++) {
 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);
 }
代码实现的效果图如下：