#!/usr/local/bin/bash
# -----------------------------------------------------------------------------
# "600 dpi scan cleaner and screen-size scaler"
# Just the thing for converting high-resolution (but very low quality) scans
# into high-quality screen-sized JPEGs.
#
# Typical usage is something like:
#
# 1. One-off operation:
#       $ scancleaner foo.png foo_screensized.jpg
#
# 2. Fix all the JPEG files in the current directory:
#       $ for i in *jpg; do echo $i; scancleaner $i ${i%.jpg}_r.Jpg; done
#
# Note that the sel-guass operations can take a _lot_ of time and memory!
# (My AthonXP2000+ can take over 9 minutes on a 2500x3500 pixel image.)
# -----------------------------------------------------------------------------
# Copyright 2003 Chris Baird <cjb@brushtail.apana.org.au>
# Bound to the GNU Public Licence Version 2.
# -----------------------------------------------------------------------------

sfile=${1}
tfile=${2-output.jpg}

twidth=1024    			# size of the output image
theight=768			# (i.e, that of most desktops)

gimp -i -b '
(begin
    
    (define (make-clean sfile tfile twidth theight)
	(let* ( (image (car (gimp-file-load 1 sfile sfile)))
		(drawable (car (gimp-image-active-drawable image)))
		(swidth (car (gimp-image-width image)))
		(sheight (car (gimp-image-height image))))

	    (if (> (* theight swidth) (* sheight twidth))
		(set! theight (* sheight (/ twidth  swidth)))
		(set! twidth (* swidth (/ theight sheight))))
	    
	    (plug-in-sel-gauss 1 image drawable 4 20)
	    (gimp-levels drawable 0 4 251 1.0 0 255)
	    (plug-in-sel-gauss 1 image drawable 16 8)
	    (gimp-image-scale image twidth theight)
	    (plug-in-sel-gauss 1 image drawable 16 4)
	    (gimp-levels drawable 0 4 251 1.0 0 255)
	    
	    (file-jpeg-save 1 image drawable tfile "" 0.95 0.1 1 1 
		"Made with GIMP" 0 1 0 2)
	    ))
    
    (make-clean "'$sfile'" "'$tfile'" '$twidth' '$theight')
    (gimp-quit 0)
)
'