...Indeed, maybe I was too focused on translating using the same words as the English ones. The main problem here is that we don't have any context - where is that going to be used ? If it is to show horizontal/vertical edges, then you're right.
However, I still think my translation of "Uploading" is a good one - look at all the French image hosting sites. They all talk about "hébergement", and since "uploading" is in a continuous tense, I think it will be shown while an image is being hosted.
+1 for the comment and screenshots - translating without knowing what it should mean is much more difficult.