Actually, no. Water absorbs most of the electromagnetic spectrum pretty well, severely limiting the communication range. So you're limited to low frequencies or acoustic communication. Both have a low bandwidth, so forget live video footage.
I am not sure you would need that much bandwidth from down there, though - I really can't see that much happening that quickly at the bottom of the Challenger Deep.
For example, what if the image was a pic of various graphs and stats of the status of the machine, but at the same time other critical information is encoded in the image of a Status-Page/Dashboard style KPI image?
How do you propose sending it?
Better yet, is if the image is of a flase map of current in-situ..
What? Why do you believe this?
From an information theory perspective, you’re talking nonsense.
Try a wiki
You need to revisit information theory and the physical and data-link layers of networking.
So an stegano can give you image ..> code ..Def=code.. image.. infor, it may require more itereations... look into it.