Posterizing With Cutout Filter
Photoshop CS6 Tutorial
How to Posterize with the Photoshop Cutout Filter
Posterizing takes a continuous tone photograph and converts it to a simplified version with limited shapes and colors.
Open an image by choosing File > Open.
From the Filter menu, choose Filter Gallery, then Artistic and Cutout.
The Cutout preview and options appear.
Adjust the sliders to enhance your image, then press OK to apply the changes.