GIMP batch process script run-time error

**Paddy Landau** · April 6th, 2014

I need a bit of help, please, with scripting a batch process for GIMP. I hope that I'm asking on the right forum; if there is a better place to ask, please point me in the right direction. (I'm an absolute beginner when it comes to GIMP scripting.)

I have a bunch of images that I wish to process with script-fu-pencil-drawing. For simplicity's sake, I'll talk about just a single image in this post.

I have used the tutorial for GIMP batch scripting. Taking the tutorial's example verbatim works perfectly. But when I adjust the script for script-fu-pencil-drawing, I get an error.

Note that script-fu-pencil-drawing works when used interactively; it is only when used in this batch script that it fails.

Here is the script as I've adjusted it. The changes are highlighted.

Code:

(define (simple-script-fu-pencil-drawing filename
                                         radius
                                         strength
                                         mergelayers)
   (let* ((image (car (gimp-file-load RUN-NONINTERACTIVE filename filename)))
          (drawable (car (gimp-image-get-active-layer image))))
          (script-fu-pencil-drawing RUN-NONINTERACTIVE
                                    image drawable radius strength mergelayers)
     (gimp-file-save RUN-NONINTERACTIVE image drawable filename filename)
     (gimp-image-delete image)))

Here is the command that I run on the command line, where foo.png is the image to be processed. Again, changes are highlighted.

Code:

gimp -i -b '(simple-script-fu-pencil-drawing "foo.png" 8.0 16.0 TRUE)' -b '(gimp-quit 0)'

Here is the output. The original foo.png is left unchanged.

Code:

GIMP-Error: Calling error for procedure 'gimp-layer-copy':
Procedure 'gimp-layer-copy' has been called with an invalid ID for argument 'layer'. Most likely a plug-in is trying to work on a layer that doesn't exist any longer.

batch command experienced an execution error:
Error: ( : 1) Procedure execution of gimp-layer-copy failed on invalid input arguments: Procedure 'gimp-layer-copy' has been called with an invalid ID for argument 'layer'.
Most likely a plug-in is trying to work on a layer that doesn't exist any longer.

I have been at this for a couple of hours, and nothing that I've tried has worked. If you could help me fix this, please, I would be most grateful.