My process of turning a Callipeg export of PNG frames into gifs and spritesheets

make-gif-from-frames.sh

export NAME="my-animation"
export WIDTH=815
export HEIGHT=950
export BG_COLOR="#d1ccff"
export SPRITESHEET_SIZE=5x3
export TINIFY_API_KEY="..."

# Assuming frames have been exported to `~/Downloads/`...

# Make directories
mkdir ~/Pictures/animations/$NAME/{original,cropped}

# Move PNG frames from `~/Downloads` to the newest directory in `~/Pictures/animations`
find ~/Downloads -maxdepth 1 -regex '.*[0-9].png' -exec mv {} ~/Pictures/animations/$(/bin/ls -t ~/Pictures/animations/ | head -n 1)/original/ \;

cd ~/Pictures/animations/$NAME/original

# Add a leading 0 in front of single-digit frames
rename 's/_(\d\.)/_0$1/g' -- *.png

# Crop the original images
mogrify +repage -crop $WIDTH"x"$HEIGHT+0+0 +repage -path ../cropped *_*.png

# Generate gif
cd ../cropped
convert -limit thread 1 -delay 4.16666666666 -alpha set -dispose previous +dither *_*.png out-transparent.gif && convert -limit thread 1 -delay 4.16666666666 *_*.png -background "$BG_COLOR" -alpha remove -alpha off +dither out.gif

# Make spritesheet
montage -border 0 -tile $SPRITESHEET_SIZE -geometry $WIDTH"x" -background none *_*.png spritesheet-unoptimized.png

# Optimize spritesheet
curl $(curl --user api:$TINIFY_API_KEY --data-binary @spritesheet-unoptimized.png https://api.tinify.com/shrink | jq -r .output.url) >spritesheet.png