Computer-generated imagery was an image created with the aid of a computer.
In 2364, William T. Riker referred to a holographic re-creation of the Bourbon Street Barn on the holodeck as a computer-generated gin joint. Despite the holographic Minuet being a computer-generated image, her smell, touch, the way she felt, and even the things she said and thought seemed so real to Riker. (TNG: "11001001")
In 2365 during a battle simulation, the crew of the USS Hathaway convinced the USS Enterprise-D's sensors that an enemy ship approached. The computer successfully projected a false image of a Romulan warbird onto the Enterprise-D's main viewscreen. (TNG: "Peak Performance")
In 2366, sensors aboard the USS Enterprise-D incorrectly indicated that a Borg vessel fired energy weapons at the ship, and it was soon discovered that no such vessel was there. Lieutenant Commander Data postulated that it had been a synthetically-generated image. (TNG: "Evolution")
In 2375, Jean-Luc Picard described a hologram as a computer-driven image created by photons and force fields. (Star Trek: Insurrection)
The 32nd century hologram Eli was computer-generated and not modeled after anyone. (DIS: "There Is A Tide...")