By Dawn Chmielewski

LOS ANGELES, June 11 (Reuters) - Walt Disney DIS.N and Comcast's CMCSA.O Universal filed a copyright lawsuit against Midjourney on Wednesday, calling its popular AI-powered image generator a "bottomless pit of plagiarism" for its use of the studios' best-known characters.

The suit, filed in federal district court in Los Angeles, claims Midjourney pirated the libraries of the two Hollywood studios, making and distributing without permission "innumerable" copies of characters such as Darth Vader from "Star Wars," Elsa from "Frozen," and the Minions from "Despicable Me".

The studios claim the San Francisco company rebuffed their request to stop infringing their copyrighted works or, at a minimum, take technological measures to halt the creation of these AI-generated characters.

Instead, the studios argue, Midjourney continued to release new versions of its AI image service that boast higher quality infringing images.

Midjourney recreates animated images from a typed request, or prompt.

In the suit filed by seven corporate entities at the studios that own or control copyrights for the various Disney and Universal Pictures film units, the studios offered examples of Midjourney animations that include Disney characters, such as Yoda wielding a lightsaber, Bart Simpson riding a skateboard, Marvel's Iron Man soaring above the clouds and Pixar's Buzz Lightyear taking flight.

The image generator also recreated such Universal characters as "How to Train Your Dragon's" dragon, Toothless, the green ogre "Shrek," and Po from "Kung Fu Panda."

"By helping itself to plaintiffs' copyrighted works, and then distributing images (and soon videos) that blatantly incorporate and copy Disney's and Universal's famous characters -- without investing a penny in their creation -- Midjourney is the quintessential copyright free-rider and a bottomless pit of plagiarism," the suit alleges.

"Midjourney's infringement is calculated and willful."

Disney and Universal asked the court for a preliminary injunction, to prevent Midjourney from copying their works, or offering its image- or video-generation service without protections against infringement. The studios also seek unspecified damages.

The suit alleges Midjourney used the studios' works to train its image service and generate reproductions of their copyrighted characters. The company, founded in 2021 by David Holz, monetizes the service through paid subscriptions and generated $300 million in revenue last year alone, the studios said.

This is not the first time Midjourney has been accused of misusing artists' work to train their AI systems.

A year ago, a California federal judge found that 10 artists behind a copyright infringement suit against Midjourney, Stability AI and other companies had plausibly argued these AI companies had copied and stored their work on company servers, and could be liable for using it without permission.

That ruling allowed the lawsuit over the unauthorized use of images to proceed. It is in the process of litigation.

In a 2022 interview with Forbes, CEO Holz said he built the company's database by performing "a big scrape of the Internet."

Asked whether he sought consent of the artists whose work was covered by copyright, he responded, "there isn't really a way to get a hundred million images and know where they're coming from."

(Editing by Sam Holmes)

((dawn.chmielewski@thomsonreuters.com))