Searching for pixelation image effect.

Hi! I'm searching for a pixelation image effect for Unity. Like [this][1]. I want to make an old-school style game, and I need that effect for it for a "better" appearence. The game itself will be 3D, but pixelated, graphically similar to Duke Nukem 3D. I have Unity Pro. I couldn't find an effect like that yet. [1]: http://www.ozone3d.net/public/jegx/201010/geexlab_pixelate_demo_02.jpg