I think JPG is the main subject, GIFs are perhaps less involved and SVG is of course problemless.
Is there a tool to hunt for overmagnified pictures and restore them? I mean when a JPG is originally 150 px and is rendered to 300 px in the article which is a useless enlargement and results in an ugly picture.
Or do we have any part of it, e.g. determining the size of a picture?