Transparent blurry view which blurs layout underneath

Question

I\'ve got a Linearlayout which I\'ve made transparent, and now I\'m looking for a way to give it a Blur effect, so what\'s ever underneath it gets blurry. Just like the Wind

Answer 1

Here is a good way to "Blur Images Efficiently using Renderscript" by GDE Mario Viviani.

Here is the copy/paste:

Blurring images is an effect a lot of developers need to achieve, and it may require some time and efforts to be implemented. Also, since a lot of image manipulation is required, if it's not appropriately coded it can be really a pain in terms of CPU and memory usage.

There's a quick and efficient solution to blur images, which is Renderscript.

Available since API 11 (Honeycomb), Renderscript allows to take advantage of the GPU acceleration and is targeted at high-performance 3D rendering and compute operations. Renderscript is a really complex and articulated product, and allows deep configuration and coding using native C99 language, which allows portability, performance and usability.

However, since API 17 (4.2.2) Renderscript offer some built-in functions that perform well-defined operations, called Intrinsics. Intrinsics are pre-written scripts that allow, to perform operations like Blur, Blen, Matrix Convolution and more, without the need to write Renderscript code.

Here's a simple method I wrote to easily end efficiently apply a Blur filter to a Bitmap:

public Bitmap blurBitmap(Bitmap bitmap) {

    //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(getApplicationContext());

    //Create an Intrinsic Blur Script using the Renderscript
    ScriptIntrinsicBlur blurScript = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));

    //Create the in/out Allocations 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(25.f);

    //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;
}

And...voilà! Blurred bitmap! :-)

Remember that to run the previous code you need minimum API 17 (4.2.2).

Here's a Gist of this method: https://gist.github.com/Mariuxtheone/903c35b4927c0df18cf8

If you want to discover more about Intrinsics, check out this post on Android Developers Blog: http://android-developers.blogspot.it/2013/08/renderscript-intrinsics.html

If you're interested in know more about Renderscript, check out these links: http://android-developers.blogspot.it/2011/02/introducing-renderscript.html http://android-developers.blogspot.it/2011/03/renderscript.html