@Ciaran
Being able to reject the cruft like obviously-backgrounded things, or pictures that are too small would be amazing, though.
>but the figure within the image is itself too short.
Not that much of a problem in principle: find the first row with non-transparent pixels, find
last row with non-transparent pixels, compare the index. Now, actually implementing that is another matter.
>as an image from PonyCreator or PonyTown with the background cut out is mathematically indistinguishable from a valid entry
Actually distinguishable (the shapes are pre-determined) but would be too much of a bother and have high failure rate.
>And explaining to people what is needed is often more than a boilerplate can accomplish …
The real problem is that if they failed to READ THE FUCKING RULES (e.g. non-white backgrounds, ponycreator pics) they’ll fail to read the boilerplate as well.
P.S. What would be great is ability to search for presence of background, e.g. “return all images with the 4 corner pixels of the image being opaque” or “return all images whose collapsed form (IIRC 4 pixels used for comparisons) has less than specific threshold of transparency”.