Process a directory of images, color correcting for printout, for TGC use

gistfile1.txt

# your source PNG files are in the input directory

mkdir -p output

for file in input/*.png; do
  filename=${file##*/}

  convert "${file}" -level "0%,100%,1.5" "output/${filename}"

  # what the heck, make them smaller, too
  # bandwidth ain't cheap

  optipng "output/${filename}"
done