package com.example.test.qtest;
import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Bitmap;
import android.os.Build;
import android.renderscript.Allocation;
import android.renderscript.Element;
import android.renderscript.RenderScript;
import android.renderscript.ScriptIntrinsicBlur;
/**
* Created by scq on 17-2-10.
*/
public class GaussianBlur {
private Context mContext;
public GaussianBlur(Context context) {
this.mContext = context;
}
@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
/**
* 高斯模糊
* 方法一 : RenderScript是Android在API 11之后加入的，用于高效的图片处理，包括模糊、混合、矩阵卷积计算等
* 优点：处理时间快
* 缺点：模糊程度比较低
* **/
public Bitmap blurRenderScriptBitmap(Bitmap bitmap){
//创建一个空位图，其大小与要模糊的位图大小相同
Bitmap outBitmap = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
//实例化一个新的Renderscript
RenderScript rs = RenderScript.create(mContext);
//使用Renderscript创建一个内在模糊脚本
ScriptIntrinsicBlur blurScript = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
//使用Renderscript和in / out位图创建分配（in / out）
Allocation allIn = Allocation.createFromBitmap(rs, bitmap);
Allocation allOut = Allocation.createFromBitmap(rs, outBitmap);
//设置模糊的半径 半径范围（1.0f ~ 25.0f）
blurScript.setRadius(25.0f);
//执行Renderscript
blurScript.setInput(allIn);
blurScript.forEach(allOut);
//将out Allocation创建的最终位图复制到outBitmap
allOut.copyTo(outBitmap);
//回收原始位图
bitmap.recycle();
//完成一切后，销毁Renderscript。
rs.destroy();
return outBitmap;
}
/**
* 高斯模糊
* 方法二 : 实现高斯模糊的效果，使用了特殊的算法
* 优点 ： 比第三种可以快很多
* 缺点 ： 比第一种（RenderScript）还是慢一些
* **/
public static Bitmap doFastBlur(Bitmap sentBitmap, int radius, boolean canReuseInBitmap) {
Bitmap bitmap;
if (canReuseInBitmap) {
bitmap = sentBitmap;
} else {
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);
}
/**
* 高斯模糊
* 方法三 : 使用矩阵处理
* 优点 ： 简单易懂
* 缺点 ： 处理速度慢
* **/
public static void gaussBlur(int[] data, int width, int height, int radius,
float sigma) {
float pa = (float) (1 / (Math.sqrt(2 * Math.PI) * sigma));
float pb = -1.0f / (2 * sigma * sigma);
// generate the Gauss Matrix
float[] gaussMatrix = new float[radius * 2 + 1];
float gaussSum = 0f;
for (int i = 0, x = -radius; x <= radius; ++x, ++i) {
float g = (float) (pa * Math.exp(pb * x * x));
gaussMatrix[i] = g;
gaussSum += g;
}
for (int i = 0, length = gaussMatrix.length; i < length; ++i) {
gaussMatrix[i] /= gaussSum;
}
// x direction
for (int y = 0; y < height; ++y) {
for (int x = 0; x < width; ++x) {
float r = 0, g = 0, b = 0;
gaussSum = 0;
for (int j = -radius; j <= radius; ++j) {
int k = x + j;
if (k >= 0 && k < width) {
int index = y * width + k;
int color = data[index];
int cr = (color & 0x00ff0000) >> 16;
int cg = (color & 0x0000ff00) >> 8;
int cb = (color & 0x000000ff);
r += cr * gaussMatrix[j + radius];
g += cg * gaussMatrix[j + radius];
b += cb * gaussMatrix[j + radius];
gaussSum += gaussMatrix[j + radius];
}
}
int index = y * width + x;
int cr = (int) (r / gaussSum);
int cg = (int) (g / gaussSum);
int cb = (int) (b / gaussSum);
data[index] = cr << 16 | cg << 8 | cb | 0xff000000;
}
}
// y direction
for (int x = 0; x < width; ++x) {
for (int y = 0; y < height; ++y) {
float r = 0, g = 0, b = 0;
gaussSum = 0;
for (int j = -radius; j <= radius; ++j) {
int k = y + j;
if (k >= 0 && k < height) {
int index = k * width + x;
int color = data[index];
int cr = (color & 0x00ff0000) >> 16;
int cg = (color & 0x0000ff00) >> 8;
int cb = (color & 0x000000ff);
r += cr * gaussMatrix[j + radius];
g += cg * gaussMatrix[j + radius];
b += cb * gaussMatrix[j + radius];
gaussSum += gaussMatrix[j + radius];
}
}
int index = y * width + x;
int cr = (int) (r / gaussSum);
int cg = (int) (g / gaussSum);
int cb = (int) (b / gaussSum);
data[index] = cr << 16 | cg << 8 | cb | 0xff000000;
}
}
}
}
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