[Gimp-user] Script-fu in GIMP - and batch processing.

["ludo0565 dbmail com" <ludo0565 dbmail com>]

Hello everyone,

As a user of GIMP 2.10, I am at the moment very interested by the possibilities to do
batch processing with script-fu in GIMP.

So I found this page and took a close look at it:
https://www.gimp.org/tutorials/Basic_Batch/

My problem is that I want to save a processed file with a new name.

So it didn't take me too much time to figure out how to do it for the first example - and
I came up with this:

(define (simple-unsharp-mask filename radius amount threshold filenamenew)
   (let* ((image (car (gimp-file-load RUN-NONINTERACTIVE filename filename)))
          (drawable (car (gimp-image-get-active-layer image))))
     (plug-in-unsharp-mask RUN-NONINTERACTIVE image drawable radius amount threshold)
     (gimp-file-save RUN-NONINTERACTIVE image drawable filenamenew filenamenew)
     (gimp-image-delete image)))
    
The procedure is being called with this command line:
gimp -i -b '(simple-unsharp-mask "foo.png" 5.0 0.5 0 "foo-new.png")' -b '(gimp-quit 0)'


Now I'm wondering how to get the second example, the actual batch processing script, to
give new names for each and everyone of the processed images.

I tried with this:

(define (batch-unsharp-mask pattern radius amount threshold patternnew)
  (let* ((filelist (cadr (file-glob pattern 1)))
         (filelistnew (cadr (file-glob patternnew 1))))
    (while (not (null? filelist))
           (let* ((filename (car filelist))
                 (filenamenew (car filelistnew))
                  (image (car (gimp-file-load RUN-NONINTERACTIVE filename filename)))
                  (drawable (car (gimp-image-get-active-layer image))))
             (plug-in-unsharp-mask RUN-NONINTERACTIVE image drawable radius amount threshold)
             (gimp-file-save RUN-NONINTERACTIVE image drawable filenamenew filenamenew)
             (gimp-image-delete image))
           (set! filelist (cdr filelist))
           (set! filelistnew (cdr filelistnew)))))

But this didn't work because a list may not be empty: I understand now that it must exist
beforehand and have at least 2 elements ("pair").

Then I tried with this:

(define (batch-unsharp-mask pattern radius amount threshold filenamenew)
  (let* ((filelist (cadr (file-glob pattern 1))))
    (while (not (null? filelist))
           (let* ((filename (car filelist))
                 (filenamenew (+ "(car filelist)" "-new"))
                  (image (car (gimp-file-load RUN-NONINTERACTIVE filename filename)))
                  (drawable (car (gimp-image-get-active-layer image))))
             (plug-in-unsharp-mask RUN-NONINTERACTIVE image drawable radius amount threshold)
             (gimp-file-save RUN-NONINTERACTIVE image drawable filenamenew filenamenew)
             (gimp-image-delete image))
           (set! filelist (cdr filelist)))))
          
But that didn't work either, because the argument to " + " (sum) must be a number.


Where am I mistaken? Could you help?

Or should I proceed in a totally different direction?

Thanks a lot in advance.

Ludo