android图片高斯模糊的方法

package com.hasen.test;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.PixelFormat;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;

public class ImageUtils {
/** 水平方向模糊度 */
private static float hRadius = 10;
/** 竖直方向模糊度 */
private static float vRadius = 10;
/** 模糊迭代度 */
private static int iterations = 7;

/**
* 高斯模糊
*/
public static Drawable BoxBlurFilter(Bitmap bmp) {
int width = bmp.getWidth();
int height = bmp.getHeight();
int[] inPixels = new int[width * height];
int[] outPixels = new int[width * height];
Bitmap bitmap = Bitmap.createBitmap(width, height,Bitmap.Config.ARGB_8888);
bmp.getPixels(inPixels, 0, width, 0, 0, width, height);
for (int i = 0; i < iterations; i++) {
blur(inPixels, outPixels, width, height, hRadius);
blur(outPixels, inPixels, height, width, vRadius);
}
blurFractional(inPixels, outPixels, width, height, hRadius);
blurFractional(outPixels, inPixels, height, width, vRadius);
bitmap.setPixels(inPixels, 0, width, 0, 0, width, height);
Drawable drawable = new BitmapDrawable(bitmap);
return drawable;
}

public static void blur(int[] in, int[] out, int width, int height,
float radius) {
int widthMinus1 = width - 1;
int r = (int) radius;
int tableSize = 2 * r + 1;
int divide[] = new int[256 * tableSize];

for (int i = 0; i < 256 * tableSize; i++)
divide[i] = i / tableSize;

int inIndex = 0;

for (int y = 0; y < height; y++) {
int outIndex = y;
int ta = 0, tr = 0, tg = 0, tb = 0;

for (int i = -r; i <= r; i++) {
int rgb = in[inIndex + clamp(i, 0, width - 1)];
ta += (rgb >> 24) & 0xff;
tr += (rgb >> 16) & 0xff;
tg += (rgb >> 8) & 0xff;
tb += rgb & 0xff;
}

for (int x = 0; x < width; x++) {
out[outIndex] = (divide[ta] << 24) | (divide<< 16)
| (divide[tg] << 8) | divide[tb];

int i1 = x + r + 1;
if (i1 > widthMinus1)
i1 = widthMinus1;
int i2 = x - r;
if (i2 < 0)
i2 = 0;
int rgb1 = in[inIndex + i1];
int rgb2 = in[inIndex + i2];

ta += ((rgb1 >> 24) & 0xff) - ((rgb2 >> 24) & 0xff);
tr += ((rgb1 & 0xff0000) - (rgb2 & 0xff0000)) >> 16;
tg += ((rgb1 & 0xff00) - (rgb2 & 0xff00)) >> 8;
tb += (rgb1 & 0xff) - (rgb2 & 0xff);
outIndex += height;
}
inIndex += width;
}
}

public static void blurFractional(int[] in, int[] out, int width,
int height, float radius) {
radius -= (int) radius;
float f = 1.0f / (1 + 2 * radius);
int inIndex = 0;

for (int y = 0; y < height; y++) {
int outIndex = y;

out[outIndex] = in[0];
outIndex += height;
for (int x = 1; x < width - 1; x++) {
int i = inIndex + x;
int rgb1 = in[i - 1];
int rgb2 = in[i];
int rgb3 = in[i + 1];

int a1 = (rgb1 >> 24) & 0xff;
int r1 = (rgb1 >> 16) & 0xff;
int g1 = (rgb1 >> 8) & 0xff;
int b1 = rgb1 & 0xff;
int a2 = (rgb2 >> 24) & 0xff;
int r2 = (rgb2 >> 16) & 0xff;
int g2 = (rgb2 >> 8) & 0xff;
int b2 = rgb2 & 0xff;
int a3 = (rgb3 >> 24) & 0xff;
int r3 = (rgb3 >> 16) & 0xff;
int g3 = (rgb3 >> 8) & 0xff;
int b3 = rgb3 & 0xff;
a1 = a2 + (int) ((a1 + a3) * radius);
r1 = r2 + (int) ((r1 + r3) * radius);
g1 = g2 + (int) ((g1 + g3) * radius);
b1 = b2 + (int) ((b1 + b3) * radius);
a1 *= f;
r1 *= f;
g1 *= f;
b1 *= f;
out[outIndex] = (a1 << 24) | (r1 << 16) | (g1 << 8) | b1;
outIndex += height;
}
out[outIndex] = in[width - 1];
inIndex += width;
}
}

public static int clamp(int x, int a, int b) {
return (x < a) ? a : (x > b) ? b : x;
}

public static Bitmap drawableToBitmap(Drawable drawable) {
Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(),drawable.getIntrinsicHeight(),
drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888: Bitmap.Config.RGB_565);
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, drawable.getIntrinsicWidth(),
drawable.getIntrinsicHeight());
drawable.draw(canvas);
return bitmap;
}
}