SAN FRANCISCO — As Google awaits approval of a controversial settlement with authors and book publishers, the company’s plan to create an immense digital library and bookstore may face yet another hurdle.

On Wednesday, the American Society of Media Photographers and other groups representing visual artists plan to file a class-action lawsuit against Google, asserting that the company’s efforts to digitize millions of books from libraries amount to large-scale infringement of their copyrights.

The lawsuit, in some respects, mirrors the complaints filed in 2005 by the Authors Guild and the Association of American Publishers when they first opposed Google’s library project on copyright grounds.

Those groups have since agreed to a sweeping $125 million settlement that, if approved, would allow Google to make available and sell digital copies of millions of out-of-print books. The settlement would also give authors and publishers new ways to make money from digital copies of their work.