#!/bin/sh

THUMB_DIR=thumb
HEIGHT=100

if [ -d $THUMB_DIR ]; then
    rm -f $THUMB_DIR/*
else
    mkdir $THUMB_DIR || exit 1
fi

scalecmd="pnmscale -ysize $HEIGHT"

exec 2>/dev/null

for f in *; do
    [ -f "$f" ] || continue
    case "$f" in
    *.[Jj][Pp][Gg] | *.[Jj][Pp][Ee][Gg])
	djpeg "$f" | $scalecmd | cjpeg >"$THUMB_DIR/$f";;
    *.[Gg][Ii][Ff])
	giftoppm "$f" | $scalecmd | ppmquant 256 | ppmtogif >"$THUMB_DIR/$f";;
    *)
	continue;;
    esac
done
.