;; batch-colorize.scm  --  applica lo strumento di colore Colora su un gruppo di file 
;; in formato png. Funziona solo con versioni di Gimp uguali o superiori alla 2.2.
;;
;; per usare lo script richiamalo, dopo averlo installato, 
;; dalla riga di comando in questo modo:
;;
;; gimp -i -b "(batch-colorize \"*.png\" 180 50 0)" "(gimp-quit 0)"
;;
;; This script uses the file-glob plug-in which is not available in GIMP 2.0.

(define (batch-colorize pattern
                            hue
                            saturation
                            lightness)
  (let* ((filelist (cadr (file-glob pattern 1))))
    (while filelist
           (let* ((filename (car filelist))
                  (image (car (gimp-file-load RUN-NONINTERACTIVE                         filename filename)))
                  (drawable (car (gimp-image-get-active-layer image))))
             (gimp-colorize RUN-NONINTERACTIVE drawable hue saturation lightness)
             (gimp-file-save RUN-NONINTERACTIVE image drawable filename filename)
             (gimp-image-delete image))
           (set! filelist (cdr filelist)))))