我需要在listview
的项目后面进行模糊 效果。期望的效果如下所示
问题是我需要一个非常快速的解决方案,以便项目可以快速滚动。
答案 0 :(得分:2)
看一下这篇博文,详细介绍几个不同的选项。
http://nicolaspomepuy.fr/blur-effect-for-android-design/
和github项目https://github.com/PomepuyN/BlurEffectForAndroidDesign
这里有趣的课程。
package com.npi.blureffect;
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.os.Build.VERSION;
import android.renderscript.Allocation;
import android.renderscript.Element;
import android.renderscript.RenderScript;
import android.renderscript.ScriptIntrinsicBlur;
import android.util.Log;
public class Blur {
private static final String TAG = "Blur";
@SuppressLint("NewApi")
public static Bitmap fastblur(Context context, Bitmap sentBitmap, int radius) {
if (VERSION.SDK_INT > 16) {
Bitmap bitmap = sentBitmap.copy(sentBitmap.getConfig(), true);
final RenderScript rs = RenderScript.create(context);
final Allocation input = Allocation.createFromBitmap(rs, sentBitmap, Allocation.MipmapControl.MIPMAP_NONE,
Allocation.USAGE_SCRIPT);
final Allocation output = Allocation.createTyped(rs, input.getType());
final ScriptIntrinsicBlur script = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
script.setRadius(radius /* e.g. 3.f */);
script.setInput(input);
script.forEach(output);
output.copyTo(bitmap);
return bitmap;
}
// 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];
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);
}
}
答案 1 :(得分:0)
如果要快速计算缩小背景的模糊版本,请轻松解决。
然后每次滚动列表时修剪它以应用小补丁作为每个项目的背景。
答案 2 :(得分:0)
我用这个来创建一个模糊图像,还包括一个用于制作的ansyctask
/ ** *由Carlos Bedoy于15/05/14创建。 * /
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Rect;
import android.os.AsyncTask;
import android.os.Build;
import android.support.v8.renderscript.Allocation;
import android.support.v8.renderscript.Element;
import android.support.v8.renderscript.RenderScript;
import android.support.v8.renderscript.ScriptIntrinsicBlur;
import android.view.View;
import org.pademobile.application.ApplicationLoader;
import java.util.concurrent.ExecutionException;
public class BlurService {
public static BlurService instance;
public static BlurService getInstance(){
if(instance == null){
instance = new BlurService();
}
return instance;
}
public Bitmap blurRenderScript(Bitmap smallBitmap)
{
Bitmap output = Bitmap.createBitmap(smallBitmap.getWidth(), smallBitmap.getHeight(), smallBitmap.getConfig());
RenderScript rs = RenderScript.create(ApplicationLoader.mainContext);
ScriptIntrinsicBlur script = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
Allocation inAlloc = Allocation.createFromBitmap(rs, smallBitmap, Allocation.MipmapControl.MIPMAP_NONE, Allocation.USAGE_GRAPHICS_TEXTURE);
Allocation outAlloc = Allocation.createFromBitmap(rs, output);
script.setRadius(25);
script.setInput(inAlloc);
script.forEach(outAlloc);
outAlloc.copyTo(output);
rs.destroy();
return output;
}
public Bitmap blurRenderScript(Bitmap smallBitmap, int radius)
{
Bitmap output = Bitmap.createBitmap(smallBitmap.getWidth(), smallBitmap.getHeight(), smallBitmap.getConfig());
RenderScript rs = RenderScript.create(ApplicationLoader.mainContext);
ScriptIntrinsicBlur script = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
Allocation inAlloc = Allocation.createFromBitmap(rs, smallBitmap, Allocation.MipmapControl.MIPMAP_NONE, Allocation.USAGE_GRAPHICS_TEXTURE);
Allocation outAlloc = Allocation.createFromBitmap(rs, output);
script.setRadius(radius > 25 ? 25 : radius);
script.setInput(inAlloc);
script.forEach(outAlloc);
outAlloc.copyTo(output);
rs.destroy();
return output;
}
public Bitmap performRequestBlurByImage(Bitmap bitmap)
{
DoAsyncBlur doAsyncBlur = new DoAsyncBlur();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
doAsyncBlur.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, bitmap);
} else {
doAsyncBlur.execute(bitmap);
}
try {
return doAsyncBlur.get();
} catch (InterruptedException e) {
return bitmap;
} catch (ExecutionException e) {
return bitmap;
}
}
public Bitmap performRequestBlurByImageWithRadius(Bitmap bitmap, int radius)
{
DoAsyncBlurWithRadius doAsyncBlur = new DoAsyncBlurWithRadius();
doAsyncBlur.setRadius(radius);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
doAsyncBlur.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, bitmap);
} else {
doAsyncBlur.execute(bitmap);
}
try {
return doAsyncBlur.get();
} catch (InterruptedException e) {
return bitmap;
} catch (ExecutionException e) {
return bitmap;
}
}
private class DoAsyncBlur extends AsyncTask<Bitmap, Void, Bitmap> {
@Override
protected Bitmap doInBackground(Bitmap... bitmaps) {
return blurRenderScript(bitmaps[0]);
}
}
private class DoAsyncBlurWithRadius extends AsyncTask<Bitmap, Void, Bitmap> {
private int radius;
public void setRadius(int radius) {
this.radius = radius;
}
@Override
protected Bitmap doInBackground(Bitmap... bitmaps) {
return blurRenderScript(bitmaps[0], radius);
}
}
}