Come promesso, ecco le procedure per inserire in Gimp uno script-fu per produrre immagini HDR.
Lo script-fu (
di Riccardo Traverso ) è una serie di azioni che permettono di creare automaticamente immagini HDR ( è un po' quelle che sono le macro in Exel).
Si inserisca col copia-incolla in un programma di scrittura questo testo:
; "Fake HDR look" is a script for The GIMP
;
; This script produces an HDR-like effect on an image
;
; The script is located in "<Image> / Script-Fu / Enhance / Fake HDR look"
;
; Last changed: 17th March 2009
;
; Copyright (C) 2009 Riccardo Traverso <gr3yfox.fw@gmail.com>
;
; --------------------------------------------------------------------
;
; Changelog:
; Version 0.1
; - Initial version
;
; --------------------------------------------------------------------
;
; 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, you can view the GNU General Public
; License version 3 at the web site
http://www.gnu.org/licenses/gpl-3.0.html; Alternatively you can write to the Free Software Foundation, Inc., 675 Mass
; Ave, Cambridge, MA 02139, USA.
;
(define (add-layer-over image
add
over)
(gimp-image-set-active-layer image over)
(gimp-image-add-layer image add -1)
)
(define (script-fu-fake-hdr theImage
theLayer
darkLayerLowInput
darkLayerOpacity
dodgeAndBurn
mergeLayers
unsharpMask)
; Enable undoing this script
(gimp-image-undo-group-start theImage)
(let* (
(softglow1 (car (gimp-layer-copy theLayer FALSE)))
(softglow2)
(darken (car (gimp-layer-copy theLayer FALSE)))
)
(gimp-drawable-set-name softglow1 "Inverted softglow 1")
(add-layer-over theImage softglow1 theLayer)
(gimp-desaturate softglow1)
(gimp-invert softglow1)
(plug-in-softglow 1 theImage softglow1 10 0.75 0.85)
(gimp-layer-set-mode softglow1 SOFTLIGHT-MODE)
(set! softglow2 (car (gimp-layer-copy softglow1 FALSE)))
(gimp-drawable-set-name softglow2 "Inverted softglow 2")
(add-layer-over theImage softglow2 softglow1)
(gimp-layer-set-opacity softglow1 50)
(gimp-layer-set-opacity softglow2 75)
(add-layer-over theImage darken softglow2)
(gimp-levels darken
HISTOGRAM-VALUE ; channel
darkLayerLowInput ; low-input
255 ; high-input
1.0 ; gamma
0 ; low-output
255 ; high-output
)
(gimp-layer-set-opacity darken darkLayerOpacity)
(if (or (= mergeLayers 1) (= dodgeAndBurn 1))
(begin
(set! theLayer (car (gimp-image-merge-down theImage softglow1 2)))
(set! theLayer (car (gimp-image-merge-down theImage softglow2 2)))
(set! theLayer (car (gimp-image-merge-down theImage darken 2)))
(if (= dodgeAndBurn 1)
(script-fu-dodge-burn theImage theLayer 10 25)
)
)
)
(if (= unsharpMask 1)
(plug-in-unsharp-mask 1 theImage theLayer 5.0 0.2 0))
(gimp-image-set-active-layer theImage theLayer)
; End undo group
(gimp-image-undo-group-end theImage)
; Update image
(gimp-displays-flush)
)
)
(script-fu-register "script-fu-fake-hdr"
"<Image>/Script-Fu/Enhance/Fake HDR look" ;"Fake HDR look"
"Enhance your image saturation and contrast"
"Riccardo Traverso"
"Copyright 2009, Riccardo Traverso"
"March 17, 2009"
""
SF-IMAGE "Image" 0
SF-DRAWABLE "Drawable" 0
SF-ADJUSTMENT "Dark layer low input level" '(100 0 255 1 10 0 0)
SF-ADJUSTMENT "Dark layer opacity" '(35 0 255 1 10 0 0)
SF-TOGGLE "Dodge and burn (force merge)" FALSE
SF-TOGGLE "Merge layers" FALSE
SF-TOGGLE "Unsharp mask" TRUE
)
bisogna salvarlo come file di testo con il nome fake-hdr.scm
A questo punto bisogna inserire lo script in Gimp.
Sotto Windows: GIMP->share->Gimp->2.0->Scripts
Sotto Linux: Home-> File system ->usr ->share ->gimp ->2.0-> scripts
click destro, appare: open as root-> inserire password , la cartella cambia colore, click destro, "incolla" ed incolli finalmente il tuo script nella cartella "scripts".
Trasformiamo questa foto in una HDR:
Si apra Gimp, si selezioni Script-fu->Enhance-> Fake HDR Look
Lasciate i parametri della finestra o provate a cambiarli a vostro piacimento.
Eventualmente potete aggiungere all'immagine la funzione "curve" (sulla diagonale iniziale cliccate un punto a circa 1/8 dall'origine e spingete col mouse verso l'alto sino ad ottenere la curva in figura).
Ecco l'elaborazione finale:
Volendo, si può variare ancora agendo su luminosità e contrasto.
Buone prove!
