java版高斯算法

摘要: 网上查了很多，大多是android的例子，或则是c，c++，而java只有一个没有实现权重的例子，毫无作用。
工作需要，而只会java，所以整合写了java的高斯模糊算法工具类

直接上util代码，改下图片路径直接可以看效果

package com.yr.feiyu.common.util;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.awt.image.PixelGrabber;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
/**
*
* <p class="detail">
* 描述：高斯模糊
* </p>
* @ClassName: GaussianBlurUtil
* @version V1.0
* @date 2016年4月20日
* @author <a href="mailto:1435290472@qq.com">zq</a>
*/
public class GaussianBlurUtil {

public static void main(String[] args) throws IOException {
BufferedImage img = ImageIO.read(new File("e:/c.jpeg"));
long start = System.currentTimeMillis();
img = blur(img, 170);
long end = System.currentTimeMillis();
ImageIO.write(img, "jpeg", new File("e:/test.jpeg"));//保存为test.jpeg文件
System.out.println("花费时间："+(end-start));
System.out.println("success");
}

/**
*
* <p class="detail">
* 功能：模糊执行方法
* </p>
* @date 2016年4月20日
* @author <a href="mailto:1435290472@qq.com">zq</a>
* @param img        原图片
* @param radius     模糊权重
* @return     模糊后图片
* @throws IOException
*/
public static BufferedImage blur(BufferedImage img,int radius) throws IOException{
int height = img.getHeight();
int width = img.getWidth();
int[] values = getPixArray(img, width, height);
values = doBlur(values, width, height, radius);
img.setRGB(0, 0, width, height, values, 0, width);
return img;
}

/**
*
* <p class="detail">
* 功能：获取图像像素矩阵
* </p>
* @date 2016年4月20日
* @author <a href="mailto:1435290472@qq.com">zq</a>
* @param im
* @param w
* @param h
* @return
*/
private static int[] getPixArray(Image im, int w, int h) {
int[] pix = new int[w * h];
PixelGrabber pg = null;
try {
pg = new PixelGrabber(im, 0, 0, w, h, pix, 0, w);
if (pg.grabPixels() != true)
try {
throw new java.awt.AWTException("pg error" + pg.status());
} catch (Exception eq) {
eq.printStackTrace();
}
} catch (Exception ex) {
ex.printStackTrace();
}
return pix;
}

/**
*
* <p class="detail">
* 功能：高斯模糊算法。
* </p>
* @date 2016年4月20日
* @author <a href="mailto:1435290472@qq.com">zq</a>
* @param pix
* @param w
* @param h
* @param radius
* @return
* @throws IOException
*/
public static int[] doBlur(int[] pix,int w,int h,int radius) throws IOException {
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;
}
}
return pix;
}
}