(define (script-fu-png2gif  num-colors infile outfile)
(let* ((img (car (file-jpg-load 1 infile infile)))
(drawable (car (gimp-image-active-drawable img))))

(gimp-convert-indexed img FS-DITHER MAKE-PALETTE num-colors FALSE FALSE "")

(file-gif-save 1 img drawable outfile outfile TRUE  0 0 0)))

(script-fu-register "script-fu-png2gif"
_"<Toolbox>/Xtns/Script-Fu/Utils/conv"
"CONV"
"Marlene Busch"
"Marlene Busch"
"2001-06-04"
""
SF-VALUE "num-colors" "256"
SF-FILENAME "Infile" "dodec000.jpg"
SF-FILENAME "Outfile" "dodec000.gif" )