Save below code to file "~/.gimp-2.8/scripts/images-scale-and-fit-canvas-to-layers.scm" and restart GIMP to use:
(define (images-scale-and-fit-canvas-to-layers in-width in-height)
(map (lambda (image)
(gimp-image-scale image in-width in-height))
(vector->list
(car
(cdr
(gimp-image-list))))))
(script-fu-register
"images-scale-and-fit-canvas-to-layers"
"Images Scale and Fit Canvas to Layers"
"
1. Open images
2. Filters=>SunDawning=>Images Scale and Fit Canvas to Layers
3. Click to make Images Scale and Fit Canvas to Layers
Equivalent to:
1. Open image
2. Scale
3. Right Click
4. Image=>Fit Canvas to Layers
5. Repeat the above process to scale all images
"
"SunDawning"
"Copyright (c) 2018 https://steemit.com/@SunDawning"
""
""
SF-ADJUSTMENT "Width" '(1366 1 100000 1 10 0 1)
SF-ADJUSTMENT "Height" '(768 1 100000 1 10 0 1) )
(script-fu-menu-register "images-scale-and-fit-canvas-to-layers" "/Filters/SunDawning")