; FU_photo_EZRedSkinFix.scm
; version 2.8 [gimphelp.org]
; last modified/tested by Paul Sherman
; 02/14/2014 on GIMP-2.8.10
; 17/10/2020 on GIMP-2.10.20
;
; tweaked for GIMP-2.4.x by Paul Sherman 10/24/2007
;
; 02/14/2014 - convert to RGB if needed
;==============================================================
;
; Installation:
; This script should be placed in the user or system-wide script folder.
;
;	Windows Vista/7/8)
;	C:\Program Files\GIMP 2\share\gimp\2.0\scripts
;	or
;	C:\Users\YOUR-NAME\.gimp-2.8\scripts
;	
;	Windows XP
;	C:\Program Files\GIMP 2\share\gimp\2.0\scripts
;	or
;	C:\Documents and Settings\yourname\.gimp-2.8\scripts   
;    
;	Linux
;	/home/yourname/.gimp-2.8/scripts  
;	or
;	Linux system-wide
;	/usr/share/gimp/2.0/scripts
;
;==============================================================
;
; LICENSE
;
;    This program 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 3 of the License, or
;    (at your option) any later version.
;
;    This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
;
;==============================================================
; Original information 
; 
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;             lyle's EZ Red Skin Fix           ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; A GIMP script-fu to perform a quick red skin fix
; technique created by lylejk of dpreview.com
;
; Creates a top layer set to Value mode and
; a second layer set to Screen mode.
;
; If you leave the "Merge Layers" box unchecked,
; the two layers will remain on the stack and you can
; adjust the opacity of the Screen layer to suit,
; then merge down if desired.
;
; With the "Merge Layers" box checked, the layers will
; automatically merge down, and the resulting layer name
; will be "Fixed with EZ Red Skin Fix".  If you have several
; similar images to adjust, you may wish to determine the
; desired opacity manually on the first image, then check
; the "Merge Layers" box to speed things up on the rest of
; the layers.  The script-fu input parameters are retained
; from one run to the next, so you won't have to change the
; opacity slider once you get it set the way you want it.
;==============================================================

 
(define (FU-EZRedSkinFix  img drawable opacity merge-flag )
    
    ; Start an undo group.  Everything between the start and the end
    ; will be carried out if an undo command is issued.
    (gimp-image-undo-group-start img)
    
    ; convert to RGB if not....
    (if (not (= RGB (car (gimp-image-base-type img))))
            (gimp-image-convert-rgb img))
            
    ;CREATE THE SCREEN LAYER
    (define screen-layer (car (gimp-layer-copy drawable 0)))
    
    ; Give it a name
    (gimp-item-set-name screen-layer "Adjust opacity, then merge this layer down first")
    
    ; Add the new layer to the image
    (gimp-image-insert-layer img screen-layer 0 0)
    
    ; Set opacity
    (gimp-layer-set-opacity screen-layer opacity)
    
    ; Set the layer mode to Screen
    (gimp-layer-set-mode screen-layer LAYER-MODE-SCREEN)
    
    ;CREATE THE VALUE LAYER 
    (define value-layer (car (gimp-layer-copy drawable 0)))
    
    ; Give it a name
    (gimp-item-set-name value-layer "Merge this layer down second")
    
    ; Add the new layer to the image
    (gimp-image-insert-layer img value-layer 0 0)
    
    ; Set opacity to 100%
    (gimp-layer-set-opacity value-layer 100 )
    
    ; Set the layer mode to Value
    (gimp-layer-set-mode value-layer LAYER-MODE-HSV-VALUE )
    
    ; NOW MERGE EVERYTHING DOWN IF DESIRED
    (if (equal? merge-flag TRUE)
        (gimp-image-merge-down img screen-layer 1 )
        ()
    )
    
    (if (equal? merge-flag TRUE)
        (define second-merge (car(gimp-image-merge-down img value-layer 1 )))
        ()
    )
    
    (if (equal? merge-flag TRUE)
        (gimp-item-set-name second-merge "Fixed with EZ Red Skin Fix")
        ()
    )
    
    ; Complete the undo group
    (gimp-image-undo-group-end img)
    
    ; Flush the display 
    (gimp-displays-flush)   
)
 
 
(script-fu-register "FU-EZRedSkinFix"
    "<Image>/Script-Fu/Photo/Enhancement/EZ Red Skin Fix"
    "Performs a red skin fix technique. Add screen layer and a value layer. \nfile:FU_photo_EZRedSkinFix.scm"
    "Script by Mark Lowry"
    "Technique by lylejk of dpreview.com"
    "2006"
    "*"
    SF-IMAGE        "Image"                                 0
    SF-DRAWABLE     "Current Layer"                         0
    SF-ADJUSTMENT   "Strength? (Screen Layer Opacity)"      '(35 0 100 1 10 0 0)
    SF-TOGGLE       "Merge layers when complete?"           FALSE
)

; end of script