Pedantically, yes, lossy compression is not 100 percent reversible. Practically, the usefulness of compression is that it does return the original content with as little loss as possible… so lossy compression is mostly reversible.

All of my other points remain unchanged by this pedantry.

You can't rip something and compress it badly enough to not violate copyright when you sell it. The point of compression is to throw away information about the original in ascending order of importance.

>You can't rip something and compress it badly enough to not violate copyright when you sell it.

While I doubt that specific case has been tested in court, arguably you could. If you created glitch art (https://en.wikipedia.org/wiki/Glitch_art) via compression artifacts, and your work was sufficiently distinct from the original work, I think you would have a reasonable case for transformative use (https://en.wikipedia.org/wiki/Transformative_use).

I'm pretty sure you were downvoted by someone who walks into MoMA and whispers to their partner that a three year old could have drawn that...

At what point does it become lossy enough that it's not protected, though? You can imagine a lossy compression algorithm that merely stores a 1 for images that are "more red" and a 0 for images that are "more blue." Such a compression algorithm would be storing some information about the thing it's compressing, but the closest reconstruction you could get from the compressed data is a red square or a blue square. Surely that's not copyright infringement? What about an algorithm that counts the fingers portrayed in an image and just reconstructs an image with the same amount of fingers? Where's the line?