mkthumbs

#!/bin/bash
#
# mkthumbs
#
# Receives a filelist on STDIN and converts each to desired geometry
# Requires GraphicsMagick
#
# Will probably work with ImageMagick by simply removing the "gm " from "gm convert"

echo "USAGE: filelist | mkthumbs 200x150"

GEOMETRY="$1"

while read -r line
do
    NEWNAME=${line/\.jpg/"-$GEOMETRY.jpg"}
    echo "Converting $line to $NEWNAME"
    gm convert "$line" -geometry "$GEOMETRY^" -gravity Center -crop "$GEOMETRY+0+0" -quality 90 "$NEWNAME"
done