I just wen't through this exact exercise for a project I'm working on where I want to figure out the best image to display from a given craigslist listing.
I used an approach most similar to Goose where I download the image to get the meta data, then get rid of odd aspect ratio images (I think I have it set to anything with bigger than a 3.0 aspect ratio, but it needs to be tweaked). I also get rid of things like 1px wide images (or anything smaller than the thumbnail I want to display).
So far it works "okay". It's far from perfect, but its WAY better than nothing.
I used an approach most similar to Goose where I download the image to get the meta data, then get rid of odd aspect ratio images (I think I have it set to anything with bigger than a 3.0 aspect ratio, but it needs to be tweaked). I also get rid of things like 1px wide images (or anything smaller than the thumbnail I want to display).
So far it works "okay". It's far from perfect, but its WAY better than nothing.