; lab-colorboost.scm
;
; Version 0.1 October 2007
;
;
; lab-colorboost implements the color boost idea here:
; http://www.dslreports.com/forum/remark,15173919
;
; This file should be put into your GIMP scripts directory.  Probably
; something like ~/.gimp/scripts or ~/.gimp-2.2/scripts (this is where
; mine is--I'm on Debian Lenny/Sid).
;
;##############################################################################
; 
; LICENSE
;
;  Copyright (C) 2007 Ben Rasmussen
;
;  lab-colorboost is free software; you can redistribute it and/or
;  modify it under the terms of the GNU General Public License as
;  published by the Free Software Foundation; either version 2, or (at
;  your option) any later version.
;  
;  lab-colorboost is distributed in the hope that it will be useful,
;  but WITHOUT ANY WARRANTY; without even the implied warranty of
;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;  General Public License for more details.
;  
;  You should have received a copy of the GNU General Public License
;  along with lab-colorboost; see the file COPYING.  If not, write to
;  the Free Software Foundation, Inc., 51 Franklin Street, Fifth
;  Floor, Boston, MA 02110-1301, USA.
;
;##############################################################################

(define (script-fu-lab-colorboost image
			drawable
			opacity
			)
	(set! drawable (car (gimp-image-get-active-layer image)))
	
	;decompose to new lab image
	(set! labimage (car (plug-in-decompose RUN-NONINTERACTIVE image drawable "LAB" 1)))

	;create array of layers
	(set! lablayers (gimp-image-get-layers labimage)) 
	(set! b_layer (aref (cadr lablayers) 0))
	(set! a_layer (aref (cadr lablayers) 1))
	(set! l_layer (aref (cadr lablayers) 2))


	;dupe layer 'B', set to overlay and merge down
	(gimp-image-set-active-layer labimage b_layer)
	(set! copy (car (gimp-layer-copy b_layer 1)))
	(set! newlayer (car (gimp-image-add-layer labimage copy -1)))
	(set! drawable (car (gimp-image-get-active-layer labimage)))
	(gimp-layer-set-mode drawable 5)
	(gimp-image-merge-down labimage drawable 0)

	;dupe layer 'A', set to overlay and merge down
	(gimp-image-set-active-layer labimage a_layer)
	(set! copy (car (gimp-layer-copy a_layer 1)))
	(set! newlayer (car (gimp-image-add-layer labimage copy -1)))
	(set! drawable (car (gimp-image-get-active-layer labimage)))
	(gimp-layer-set-mode drawable 5)
	(gimp-image-merge-down labimage drawable 0)

	;merging changes layer id, so reset
	(set! lablayers (gimp-image-get-layers labimage)) 
	(set! b_layer (aref (cadr lablayers) 0))
	(set! a_layer (aref (cadr lablayers) 1))
	(set! l_layer (aref (cadr lablayers) 2))

	;compose to new image
	(set! composeimage (car (plug-in-drawable-compose 1 labimage l_layer a_layer b_layer drawable "LAB")))

	;copy composed image to new layer on original image
	(set! drawable (car (gimp-image-get-active-layer composeimage)))
	(set! copy (car (gimp-layer-new-from-drawable drawable image)))
	(set! newlayer (car (gimp-image-add-layer image copy -1)))

	;clean up tmp images
	(gimp-image-delete labimage)
	(gimp-image-delete composeimage)
	(gimp-displays-flush)

	(set! drawable (car (gimp-image-get-active-layer image)))
	(gimp-layer-set-opacity drawable opacity)
)

(script-fu-register "script-fu-lab-colorboost"
		    _"_LAB Colorboost"
		    "Gives a boost to colors using LAB image mode"
		    "Ben Rasmussen <ben@rasmussenphoto.com>"
		    "Ben Rasmussen"
		    "10/5/2007"
		    "RGB* GRAY*"
		    SF-IMAGE       "Input image"    0
		    SF-DRAWABLE    "Input drawable" 0
		    SF-ADJUSTMENT "Opacity"          '(30 1 100 1 10 0 1))

(script-fu-menu-register "script-fu-lab-colorboost"
			 _"<Image>/Script-Fu/Decor")