How to add vignette in GIMP ScriptFu

Besides wrting code I’m also amateur photographer (you can see my photos on flickr most of them released under creative commons attribution share alike license) and start adding Vignette in GIMP (the only option because I’m working on GNU/Linux).

To add vignette you can do this steps:

1. Add ellipse selection
2. Feather it by 1000 pixels (I have 24MP camera) for your case it may be larger or smaller
3. Inverse the Mask
4. Add new black layer
5. Add layer mask from selection
6. Make it 50% opacity
7. remove the selection

And now you have vignette on the image. It was fine but I needed to repeat those steps on each image, and since GIMP have support for scripting using script-fu (variant of scheme), I thought that I add simple script for the steps, here is result:

(define (make-vignette size opacity img)
  (let* ((width (car (gimp-image-width img)))
         (height (car (gimp-image-height img)))
         (layer (car (gimp-layer-new img width height 0 "vignette" 100 DARKEN-ONLY-MODE))))
    (gimp-selection-clear img)
    (gimp-image-select-ellipse img 0 0 0 width height)
    (gimp-selection-feather img size)
    (gimp-selection-invert img)
    (gimp-layer-set-opacity layer opacity)
    (gimp-layer-add-mask layer (car (gimp-layer-create-mask layer ADD-SELECTION-MASK)))
    (gimp-selection-clear img)
    (gimp-image-insert-layer img layer 0 -1)))

(script-fu-register
  "make-vignette"
  "Vignette"
  "Create Vignette for the image"
  "Jakub Jankiewicz"
  "Copyright (c) 2017 Jakub Jankiewicz <http://jcubic.pl/me>"
  "May 20, 2017"
  RGB
  SF-VALUE "Size" "1000"
  SF-VALUE "Opacity" "50"
  SF-IMAGE "image" 0
)
(script-fu-menu-register "make-vignette" "<Image>/Filters/Light and Shadow")

I’ve save it in ~/gimp-2.8/scripts/vignette.scm and it added menu item Vignette to menu Light and Shadow in Filters menu

and after I’ve executed the script I’ve get the same vignette layer with mask like this: