高斯模糊的Java实现

1、http://jhlabs.com/ip/index.html

public static byte[] blur(byte[] data) throws IOException {
        ByteArrayInputStream bais = new ByteArrayInputStream(data);
        BufferedImage img = ImageIO.read(bais);
        GaussianFilter gaussianFilter = new GaussianFilter();
        gaussianFilter.filter(img, img);
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ImageIO.write(img, "jpg", baos);
        return baos.toByteArray();
    } 

Maven地址：http://mvnrepository.com/artifact/com.jhlabs/filters

除了高斯模糊，这人还写了好多图片处理的filter，参见：http://jhlabs.com/ip/filters/index.html

2、别人写的一个类，也很赞

package com.extr.util;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.awt.image.PixelGrabber;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

public class GaussianBlurUtil {

    public static byte[] blur(byte[] data) throws IOException {
        ByteArrayInputStream bais = new ByteArrayInputStream(data);
        BufferedImage img = ImageIO.read(bais);
        img = blur(img, 50);
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ImageIO.write(img, "jpg", baos);
        return baos.toByteArray();
    }

    /**
     * 模糊执行方法
     *
     * @param img    原图片
     * @param radius 模糊权重
     * @return 模糊后图片
     */
    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;
    }

    /**
     * 获取图像像素矩阵
     *
     * @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;
    }

    /**
     * 高斯模糊算法。
     *
     * @param pix
     * @param w
     * @param h
     * @param radius
     * @return
     */
    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++) {
                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;
    }
}