本文实例讲解了android 虚化图片、模糊图片、图片毛玻璃效果的实现方法，具体内容如下
效果如图：
在android可以用renderscript方便的实现这个方法：
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private void blur(bitmap bkg, view view, float radius) { bitmap overlay = bitmap.createbitmap(view.getmeasuredwidth(), view.getmeasuredheight(), bitmap.config.argb_8888); canvas canvas = new canvas(overlay); canvas.drawbitmap(bkg, -view.getleft(), -view.gettop(), null); renderscript rs = renderscript.create(this); allocation overlayalloc = allocation.createfrombitmap(rs, overlay); scriptintrinsicblur blur = scriptintrinsicblur.create(rs, overlayalloc.getelement()); blur.setinput(overlayalloc); blur.setradius(radius); blur.foreach(overlayalloc); overlayalloc.copyto(overlay); view.setbackground(new bitmapdrawable(getresources(), overlay)); rs.destroy(); } |
但是renderscript的这个方法需要android api17，也就说需要在android 4.2上才能实现。
低于android4.2可以用java原生代码实现。但是效率会低不少：这完全是一种妥协的方式，不推荐。
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/* * this method was copied from http://stackoverflow.com/a/10028267/694378. * the only modifications i've made are to remove a couple of log * statements which could slow things down slightly. */ public bitmap fastblur(bitmap sentbitmap, int radius) { // 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 // it creates much better looking blurs than box blur, but is // 7x faster than my gaussian blur implementation. // // i called it stack blur because this describes best how this // filter works internally: it creates a kind of moving stack // of colors whilst scanning through the image. thereby it // just has to add one new block of color to the right side // of the stack and remove the leftmost color. the remaining // 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: // // 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]; 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); } |
以上就是本文的全部内容，希望对大家学习android软件编程有所帮助。
