[Gimp-user] Image transformation batch processing

[lloyd_borrett <forums gimpusers com>]

G'day,

I have many directories of images, totaling more than 5000 images in total.
Each image might be in a jpg, gif or png file format.
I want to change all images to have a 1:1 aspect ratio, on a white background.
I want no image to exceed 1000 x 1000 pixels at 72 dpi.
Images already within the 1000x1000 limit should be extended to have a 1:1
aspect ratio, as required.
At no point is any image scaled upwards in size.
All images should be saved in a suitably compressed way for displaying on web
sites.
The new images should be written into a sub-directory, with the original images
being left in place and unchanged.
Would like to do this as a single batch process, if needs be per directory.

Here are some examples as to what should happen:

1200x1200: Image re-sized to 1000x1000. Save compressed.

1600x1200: Image re-sized to 1000x750. Then extended to 1000x1000, centred on a
white background. Save compressed.

1200x1600: Image re-sized to 750x1000. Then extended to 1000x1000, centred on a
white background. Save compressed.

750x750: Save compressed.

800x600: Image extended to 800x800, centred on a white background. Save
compressed.

600x800: Image extended to 800x800, centred on a white background. Save
compressed.

Is it possible to achieve the above using Gimp?

If so, how?

If not, can you please recommend a image processing tool that can do this?

Best regards, Lloyd Borrett.

-- 
lloyd_borrett (via www.gimpusers.com/forums)