resize_images.sh

#!/bin/bash

OUTPUTDIR=.
MAXSIZE=2048

usage(){
        echo Usage: $(basename $0) [-s maxsize] [-o outputdir] jpg_file [...] 
        echo -s: max resolution [default: 2048]
        echo -o: output directory [defalut: ./ ]
}

while getopts 's:o:h' args $*
do
        case $args in
                s)
                        SIZE=$OPTARG
                        ;;
                o)
                        OUTPUTDIR=$OPTARG
                        ;;
                h|?)
                        usage
                        exit 1
                        ;;
        esac
done
shift $(($OPTIND - 1))


for i in $*
do
        BASENAME=$(basename $i)
        BASENAME=${BASENAME%.*}
        IDENTIFY=$(identify $i)
        FILETYPE=$(echo $IDENTIFY|awk '{print $2}')
        GEOMETRY=$(echo $IDENTIFY|awk '{print $3}')
        WIDTH=$(echo $GEOMETRY|awk 'BEGIN{ FS="x";}{print $1}')
        HEIGHT=$(echo $GEOMETRY|awk 'BEGIN{ FS="x";}{print $2}')

        if [ "JPEG" != $FILETYPE ]; then
                continue
        fi
        #echo "GEOMETRY=$GEOMETRY WIDTH=$WIDTH HEIGHT=$HEIGHT"

        if [ $(( $WIDTH <= $MAXSIZE && $HEIGHT <= $MAXSIZE)) -eq 0 ]; then
                echo convert $i to $OUTPUTDIR/$BASENAME.jpg
                convert -adaptive-resize ${MAXSIZE}x${MAXSIZE} $i $OUTPUTDIR/$BASENAME.jpg
        else
                echo copy $i to $OUTPUTDIR/$BASENAME.jpg
                cp $i $OUTPUTDIR/$BASENAME.jpg
        fi
done