Android 用 RenderScript 高斯模糊后，花成一片，到底咋回事儿？有没有大神来解答一下，谢谢！

代码如下：

    private static Bitmap rsBlur(Context context, Bitmap source, int radius){

    //(1)
    RenderScript renderScript =  RenderScript.create(context);

    // Allocate memory for Renderscript to work with
    //(2)
    final Allocation input = Allocation.createFromBitmap(renderScript, source);
    final Allocation output = Allocation.createTyped(renderScript,input.getType());
    //(3)
    // Load up an instance of the specific script that we want to use.
    ScriptIntrinsicBlur scriptIntrinsicBlur = ScriptIntrinsicBlur.create(renderScript, Element.U8_4(renderScript));
    //(4)
    scriptIntrinsicBlur.setInput(input);
    //(5)
    // Set the blur radius
    scriptIntrinsicBlur.setRadius(radius);
    //(6)
    // Start the ScriptIntrinisicBlur
    scriptIntrinsicBlur.forEach(output);
    //(7)
    // Copy the output to the blurred bitmap
    output.copyTo(source);
    //(8)
    renderScript.destroy();

    return source;

}

效果如下

照片是把drawable转为bitmap，然后再进行模糊化处理，结果就成这样了，有没有大神来看看咋回事啊？