For kicks, I’ve been playing around with the 8-bit pixelate effect; you know, to make your pictures look like they came out of an original Nintendo system. Here’s an example:

With a little experimentation, I’ve found a procedure that seems to work well:
- Crop your picture to whatever you want to 8-bit
- Resize by a multiple of 2, using best quality. For normal pictures I do 1/8 (12%) or 1/16 (6%) size.
- Increase the contrast (I increase by at least 30/100)
- Convert the picture to use 32 – 64 colours. This depends a bit on your content, but you don’t want to make it look completely black & white.
- Resize up to the original size (i.e., 800% or 1600%) using nearest neighbor algorithm.
And now you’ll be in 8-bit glory!