JD-EE,
"Centrosphere, what you are seeing is compression artifacts."
Good take, but what kind of compression technique these cameras utilize? I really doubt it will be something different from the standard JPEG 4, what is a quite developed standard and delivers high picture quality. Alas, the ROV is tethered, they probably donīt have a problem with bandwidth.
Actually, this is an excerpt from a report concerning the use of the Remora 6000 in the Tictanic shipwreck:
"Fiber optic technology played a major role in the research. One of the robotic submarines, the Remora 6000, which can reach the depths of 6,000 meters, was attached to the research ship, the RV Jean Charcot, by a fiber-optic tether. Telecast Fibers tiny three-inch long Rattler 3G was used aboard the Remora 6000 to transmit high-definition and 3D HDTV video and other data via fiber up to the ship."
Telecast Fiber Helps Transmit 3D Video from the Titanic - Telecast Fiber Systems - pitchengine.com
Of course I donīt know if this is the same technology they are using now, but you can see the magnitude of the file sizes involved when you have fiber optics.