How do I resize an animated GIF using nearest-neighbor interpolation?

Question

I'd like to resize an animated GIF image of some pixel art.

I'm on macOS and am comfortable with the command-line.

Answer 1

I used Gifsicle to do this. You can install it with homebrew.

brew install gifsicle

Then, to resize an image using nearest-neighbor interpolation, run

gifsicle --resize 512x512 --resize-method sample doodle002.gif > doodle002-big.gif

From the manual for the --resize-method parameter:

The ‘sample’ method is a point sampler. Each pixel position in the output image maps to exactly one pixel position in the input, so when shrinking, full rows and columns from the input are dropped.

Even though this doesn't explicitly say "nearest-neighbor interpolation" the described method sounds exactly like nearest-neighbor.