Gimp
Contents
Autocrop PNG images
Source: Batch Autocrop png Images in Gimp
1. Find the script folder
Open Gimp and within the top menu bar select Edit\Preferences\Folders, expand Folders out and Select "Scripts".
for instance: ~/.config/GIMP/2.10/scripts
2. Create the following script (batch-autocrop.scm)
(define (batch-autocrop 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-get-active-layer image))))
(plug-in-autocrop RUN-NONINTERACTIVE
image drawable)
(gimp-file-save RUN-NONINTERACTIVE
image drawable filename filename)
(gimp-image-delete image))
(set! filelist (cdr filelist)))))
3. Run the script!
gimp -i -b '(batch-autocrop "*.png")' -b '(gimp-quit 0)'