1. Open the image you want to pixelate in Photoshop.
2. Duplicate the layer by dragging the layer to the "Create a New Layer" icon in the layers palette (or CTRL+J).
3. With the copied layer selected, go to Filter > Texture > Patchwork.
4. On the Patchwork pop-up screen, change to the following values:
Square Size: 1
Relief: 0
5. You're done. You should now have a pixelated version of your image.
