1. 软件模糊

用软件的方法。利用cpu计算，无sdk版本号要求。

效果图：

关键模糊代码

原文

译文

演示样例

本文地址 ：

2. 使用RenderScript模糊，

ScriptIntrinsicBlur要求android sdk版本号最低17。

google的官方文档

具体使用代码例如以下：

/**     * 通过调用系统高斯模糊api的方法模糊     *     * @param bitmap    source bitmap     * @param outBitmap out bitmap     * @param radius    0 < radius <= 25     * @param context   context     * @return out bitmap     */ public static Bitmap blurBitmap(Bitmap bitmap, Bitmap outBitmap, float radius, Context context) {        //Let's create an empty bitmap with the same size of the bitmap we want to blur        //Bitmap outBitmap = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888);        //Instantiate a new Renderscript        RenderScript rs = RenderScript.create(context);        //Create an Intrinsic Blur Script using the Renderscript        ScriptIntrinsicBlur blurScript = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));        //Create the Allocations (in/out) with the Renderscript and the in/out bitmaps        Allocation allIn = Allocation.createFromBitmap(rs, bitmap);        Allocation allOut = Allocation.createFromBitmap(rs, outBitmap);        //Set the radius of the blur        blurScript.setRadius(radius);        //Perform the Renderscript        blurScript.setInput(allIn);        blurScript.forEach(allOut);        //Copy the final bitmap created by the out Allocation to the outBitmap        allOut.copyTo(outBitmap);        //recycle the original bitmap//        bitmap.recycle();        //After finishing everything, we destroy the Renderscript.        rs.destroy();        return outBitmap;    }

3. bitmap缩放处理

以上两种模糊方法，bitmap尺寸越小，处理的越迅速。特别是方法一。为了达到须要的模糊效果，通常我们须要对源bitmap缩放的处理。缩放代码例如以下：

/**     * 比例压缩图片     *     * @param sourceBitmap 源bitmap     * @param scaleFactor  大于1。将bitmap缩小     * @return 缩小scaleFactor倍后的bitmap     */    public static Bitmap compressBitmap(Bitmap sourceBitmap, float scaleFactor) {        Bitmap overlay = Bitmap.createBitmap((int) (sourceBitmap.getWidth() / scaleFactor),                (int) (sourceBitmap.getHeight() / scaleFactor), Config.ARGB_8888);        Canvas canvas = new Canvas(overlay);        canvas.translate(0, 0);        canvas.scale(1 / scaleFactor, 1 / scaleFactor);        Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);        canvas.drawBitmap(sourceBitmap, 0, 0, paint);        return overlay;    }

4. 改变图片的对照度/明暗度

具体说明见代码凝视，演示样例代码

/**     * 改变图片对照度,达到使图片明暗变化的效果     *     * @param srcBitmap source bitmap     * @param contrast  图片亮度。0：全黑。小于1，比原图暗；1.0f原图；大于1比原图亮     * @return bitmap     */    public static Bitmap darkBitmap(Bitmap srcBitmap, float contrast) {        float offset = (float) 0.0; //picture RGB offset        int imgHeight, imgWidth;        imgHeight = srcBitmap.getHeight();        imgWidth = srcBitmap.getWidth();        Bitmap bmp = Bitmap.createBitmap(imgWidth, imgHeight, Config.ARGB_8888);        ColorMatrix cMatrix = new ColorMatrix();        cMatrix.set(new float[]{contrast, 0, 0, 0, offset,                0, contrast, 0, 0, offset,                0, 0, contrast, 0, offset,                0, 0, 0, 1, 0});        Paint paint = new Paint();        paint.setColorFilter(new ColorMatrixColorFilter(cMatrix));        Canvas canvas = new Canvas(bmp);        canvas.drawBitmap(srcBitmap, 0, 0, paint);        return bmp;    }