"IQ Engines is joining the Flickr team at Yahoo," the startup said in a message at its website.
"As longtime Flickr fans and fellow photography enthusiasts, we look forward to working on improving photo organization and search for the community."
IQ Engines is known for software that analyzes, sorts, and categorizes images using techniques including facial recognition.
In May, Yahoo unveiled a dusted-off design of its Flickr photo platform with chief executive Marissa Mayer saying her goal was to make the online service "awesome again."
Sunnyvale, California-based Yahoo has been on a buying spree since Mayer became chief last year with a mission to revive the withering Internet pioneer.
The list of more than 20 acquisitions includes Qwiki, a New York operation behind an application that converts video and pictures on iPhones into sharable movie clips complete with music soundtracks.
Yahoo in June completed a billion-dollar deal taking over the popular blogging platform Tumblr, a move aimed at bringing more youthful users into the company's orbit.
Mayer's plan for reviving Yahoo's fortunes includes making priorities of mobile devices, video, personalized digital content, and elevating the company's popularity outside the United States.
Yahoo shares were boosted last week by a survey showed the struggling Internet giant topped a survey for US Web visitors for the first time since 2011.
In late afternoon trading Monday, Yahoo was trading down fractionally at $27.97.
The comScore survey showed Yahoo edged past Google with 195.6 million unique US Web visitors. It was the first time Yahoo was on top since May 2011. The figures exclude Yahoo's newly acquired Tumblr blog sites.