batch resize images with gimp

Question

I want to resize every jpg in a directory.

This is the gimp script I've found. Looks sensible to me.

(define (batch-resize pattern)
    (let* 
        ((filelist (cadr (file-glob pattern 1))))
        (while (not (null? filelist))
            (let* (
                    (filename (car filelist))
                    (image (car (gimp-file-load RUN-NONINTERACTIVE filename filename)))
                    (drawable   (car (gimp-image-active-drawable image)))
                    (cur-width  (car (gimp-image-width image)))
                    (cur-height (car (gimp-image-height image)))
                    (width      (* 0.25 cur-width))
                    (height     (* 0.25 cur-height))
                )
                (gimp-message filename)
                (gimp-image-scale-full image width height INTERPOLATION-CUBIC)
                (let 
                    ((nfilename (string-append "thumb_" filename)))
                    (gimp-file-save RUN-NONINTERACTIVE image drawable nfilename nfilename)
                )
                (gimp-image-delete image)
            )
            (set! filelist (cdr filelist))
        )
    )
)

I saved this as C:\Users\rwb\.gimp-2.8\scripts\batch-resize.scm and then call

"C:\Program Files\GIMP 2\bin\gimp-console-2.8.exe" -i -b '(batch-resize "*.JPG")' -b '(gimp-quit 0)'

The ouptut is

    >"C:\Program Files\GIMP 2\bin\gimp-console-2.8.exe" -i -b '(batch-resize "*.JPG")' -b '(gimp-quit 0)'
(gimp-console-2.8.exe:7568): LibGimpBase-WARNING **: gimp-console-2.8.exe: gimp_wire_read(): error
batch command executed successfully
batch command executed successfully

At which point it just hangs.

I was expecting the (gimp-message filename) to print the filenames but nothing!

I really have no idea what is going on here! Can you offer any suggestions? Even printing the filenames would be a start.

Gimp is complete overkill for this. You should really be using ImageMagick's convert. Something like convert in.jpg -resize 25% out.jpg. — xenoid

arx arx · Accepted Answer · 2019-08-21T21:32:04

The problem arises from the way you are quoting the command-line. This should work:

"c:\Program Files\GIMP 2\bin\gimp-console-2.10.exe" -b "(batch-resize \"*.JPG\")" -b "(gimp-quit 0)"

Note that it is updated for GIMP 2.10. Additionally, user script files now live in:

c:\Users\rwb\AppData\Roaming\GIMP\2.10\scripts

And finally, the code block in your question was formatted with the final parenthesis outside the block, which made it easy to miss. I've updated that.

batch resize images with gimp

1 Answers