Automatically generate all non-retina images

retina2nonretina.sh

#!/bin/bash
# Downsamples all retina [email protected] images.
 
echo "Downsampling retina images..."
 
dir=$(pwd)
find "$dir" -name "*@2x.png" | while read image; do
 
    outfile=$(dirname "$image")/$(basename "$image" @2x.png).png
 
    if [ "$image" -nt "$outfile" ]; then
        basename "$outfile"
 
        width=$(sips -g "pixelWidth" "$image" | awk 'FNR>1 {print $2}')
        height=$(sips -g "pixelHeight" "$image" | awk 'FNR>1 {print $2}')
        sips -z $(($height / 2)) $(($width / 2)) "$image" --out "$outfile"
 
        test "$outfile" -nt "$image" || exit 1
    fi
done