#!/bin/sh

# Generates thumbnail images from jpeg image(s).
# Mon Sep 18 13:14:35 CDT 2000
#
# usage: jpegtothumb <scale> <file(s)>
#
#	<scale> : a value between 0.0 and 1.0.
#		For example, 0.1 is 10% of the original size
#	<file(s)> : a list of files, or a single file.
#	
#	input: an ordinary jpeg file
#	output: thumbnail image (jpeg format) 
#		filename.jpg will result in filename-t.jpg
#
#	This program requires these commands:
#		djpeg and cjpeg : libjpeg (rpm or installed from source)
#		pnmscale	: libgr-progs (rpm) or netpbm installed from 
#				  source
#	
#	Example usage:
#		jpegtothumb 0.2 file1.jpg file2.jpg
#			-> 20% sized thumbnails of file1.jpg and file2.jpg
#		jpegtothumb 0.1 *.jpg
#			-> 10% sized thumbnails of all jpeg files in the
#			   directory
# Author : Yoonsuck Choe <yschoe@cs.utexas.edu>
# URL	 : http://www.cs.utexas.edu/users/yschoe/scripts.shtml
# License and warranty: Gnu Public License (http://www.gnu.org)


# Check for arguments
if [ $# != 0 ] ; then
  echo
else
  echo "usage: jpegtothumb <scale> <files> ..."
  exit
fi

# Set scale
scale=$1
shift

# Iterate for all files
while [ $# != 0 ] ; do

  echo
  echo "*** Processing : $1 ***"
  # jpeg2ps $1 > tmp.ps
  # pstopnm tmp.ps
  djpeg -pnm $1 > tmp.ppm
  # pnmrotate -90 tmp001.ppm > tmp.ppm 
  pnmscale $scale tmp.ppm | cjpeg > `basename $1 .jpg`-t.jpg
  shift

done
# rm tmp.ps
rm tmp.ppm
# rm tmp001.ppm