安卓实现高斯模糊

关于如何对图片进行模糊处理，网上方法比较多，常用而又便捷的方法就是使用高斯模糊，但网上的方法大多效果并不理想，今天分享一个之前项目中用到的模糊处理方法来实现高斯模糊，好了，先看模糊效果：

原图：

模糊：

注意点：

对图片的各种处理大多数是通过bitmap进行操作的，本例也不例外，另外本例是使用imageloader加载的网络图片，以给大家一个模糊网络图片的参考，当然，加载网络图片必然是异步的，所以首次进入界面加载图片时会有一个等待时间，如果想要完美用户体验的话，就需要大家开动脑筋了！

高斯封装工具类：

BitmapBlurUtil:

package com.byl.blur;


import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Handler;
import android.os.Message;


public class BitmapBlurUtil {
    private static ExecutorService executor;

    private static int POOL_SIZE = 2;// 单个CPU线程池大小

    private static ExecutorService getExecutor() {
        if (executor == null) {
            int cpuNums = Runtime.getRuntime().availableProcessors();
            executor = Executors.newFixedThreadPool(cpuNums * POOL_SIZE);
        }
        return executor;
    }

    public static void addTask(Bitmap bitmap, Handler handler) {
        getExecutor().submit(new BitmapVagueTask(bitmap, handler));
    }

    /** 水平方向模糊度 */
    private static float hRadius = 3;
    /** 竖直方向模糊度 */
    private static float vRadius = 3;
    /** 模糊迭代度 */
    private static int iterations = 5;

    /**
     * 异步
     * @author baiyuliang
     */
    private static class BitmapVagueTask implements Runnable {
        private Bitmap bitmap;
        private Handler handler;

        public BitmapVagueTask(Bitmap bitmap, Handler handler) {
            super();
            this.bitmap = bitmap;
            this.handler = handler;
        }

        @Override
        public void run() {
            boxBlurFilter(bitmap, handler);

        }

    }

    /**
     * 高斯模糊
     * 
     * @param bmp
     * @return
     */
    private static void boxBlurFilter(Bitmap bmp, Handler handler) {
        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);
        if (handler != null) {
            @SuppressWarnings("deprecation")
            Drawable drawable = new BitmapDrawable(bitmap);
            Message message = new Message();
            message.obj = drawable;
            handler.sendMessage(message);
        }

    }
    private 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[tr] << 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;
        }
    }

    private 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;
    }
}

模糊程度可以调节类中的hRadius，vRadius，iterations，三个变量！使用方法：

        //加载网络图片并得到bitmap
        ImageLoader.getInstance().loadImage("http://www.2cto.com/meinv/uploads/160328/1-16032Q42211962.jpg", new ImageLoadingListener() {
            @Override
            public void onLoadingStarted(String imageUri, View view) {
            }
            @Override
            public void onLoadingFailed(String imageUri, View view,FailReason failReason) {
            }
            @Override
            public void onLoadingComplete(String imageUri, View view, final Bitmap loadedImage) {
                if(loadedImage!=null){
                    //模糊处理
                    BitmapBlurUtil.addTask(loadedImage, new Handler(){
                        @Override
                        public void handleMessage(Message msg) {
                            super.handleMessage(msg);
                            Drawable drawable = (Drawable) msg.obj;
                            iv_blur.setImageDrawable(drawable);
                            loadedImage.recycle();
                        }
                    });
                }
            }
            @Override
            public void onLoadingCancelled(String imageUri, View view) {

            }
        });

ECdemo下载地址：http://download.csdn.net/detail/baiyuliang2013/9512311