Quoting Julian Bryson <jules...@gmail.com>:
> In short, how can I use GIMP to add blank space to a given photo so that it
> keeps the original data within the confines of a 4x6 (for example) aspect
I recently wrote a script which should facilitate your task. The
script will scale the active layer to fit within the selection -- or
the image itself if there is no selection -- while maintaining the
aspect ratio of the original layer.
If you download the file at the following location and save it to your
.gimp-2.6/scripts folder, then the next time you open GIMP there will
be a new command called "Fit to Selection" under your Layer Menu.
You would use the script by opening your original (square) image,
using "Image->Canvas Size" to set the image dimensions to 4"x6" (for
example), and then perform "Layer->Fit to Selection".
More information is available at the following link:
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