Command-line computer vision.

[Linux for blind general discussion]

Okay, I'm aware of Tesseract and cuneiform for doing OCR on image
files, but I was wondering if anyone on this list knew of any
command-line utilities that might be able to tell me useful things
about the contents of images that contain no text. Even something as
simple as printing the image's palette in descending order of
abundance or recognition of basic geometric shapes would be useful I
think.

My primary use case is giving meaningful filenames to digital photos
where I know what photos are in the set, but not which photo is which,
and primarily, the photos are of crafts I've made and taken with the
camera my portable mediaplayer/talking eReader uses for OCRing print
documents(the device gives the photos very long, numeric filenames
that might be timestamps, but even that isn't of much use if I take
more than one photo in a round of blind photography and transferring
photos to my Desktop, especially since the device's clock resets to
midnight the moringing of January 1, 2014 whenever the battery is
pulled out).

I've tried googling and searching the package lists in Aptitude, but
all I've managed to find are libaries for writing computer vision code
into reobotics projects or cloud-based complex object AI stuff.