Lens blur effect

[Dusan Paulovic]

Hi all, I am searching the web and can not find any fast way to apply Lens Blur effect like in PhotoShop. For now, I have used convolution matrix with shape drawn to kernel, but it is very slow compared to Photoshop's one. I have read many stuff on net about speeding up 2D Convolution process, but the most interesting seems to be using of GPU, but can not find any example... Another way I can imagine is to use somehow HLSL to modify texture and then convert it back to bitmap, but still do not know how to do that... Can anybody point me into right direction? Thanks in advance...

[enhzflep]

I'd suggest a google search for "hlsl convolve filter." If you haven't looked at GPUgems yet, you should check out Chapter 27 of GPUgems 2. 27.1.1 has information regarding how to select the pixels that are neighbours to the pixel in question. If you download Demoniak, there's a fist-full of examples at http://www.ozone3d.net[^]