From PNG files generated by PowerPoint to an animated GIF image

pngtogif.sh

#!/bin/zsh

# スライド1.PNG ... スライド27.PNG
# => slide__01.png ... slide__27.png
# => result.gif

if [ 1 = 1 ]
then
    for i in {1..27}
    do
        echo $i
        # echo mv $(printf "スライド%d.PNG" i) $(printf "slide__%02d.png" i)
        convert -geometry 400x300! $(printf "スライド%d.PNG" i) -fill none -stroke darkgreen -draw 'rectangle 0,0 399,299' $(printf "slide__%02d.png" i)
    done
fi

echo "making animated GIF"
convert -geometry 400x300! -delay 250 -loop 0 -colors 32 slide__*.png result.gif