Android模糊效果总结

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 github链接

原文 链接

译文 链接

演示样例 代码

本文地址 ：http://blog.csdn.net/csqingchen/article/details/43817975

2. 使用RenderScript模糊，

ScriptIntrinsicBlur要求android sdk版本号最低17。

google的官方文档链接

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;

    }