Microsoft announced today that it's acquired VideoSurf, a San Mateo, Calif.-based company that allows users to search and watch online videos.

VideoSurf "offers a back-end computer vision technology that 'sees' frames inside videos" as it searches. Microsoft said in its statement that it plans to integrate this technology into Xbox 360 and Xbox Live.

"VideoSurf's content analytics technology will enhance the search and discovery of entertainment content across our platform," Alex Garden, Microsoft's director of Xbox Live for the Interactive Entertainment Business, said in the statement. "This holiday we will launch voice search across our entertainment partners on Xbox Live. Over time, as we integrate VideoSurf's technology into our system, we are excited about the potential to have content tagged in real time to increase the speed and relevance of the search results."

Microsoft's statement did not say how much it's paying to acquire VideoSurf. But TechCrunch Europe, citing a source who requested anonymity, put the price at $70 million. [Update 11/23: TechCrunch, citing "a solid source," is now reporting the purchase price at just under $100 million.]

We have a request in to Microsoft to confirm and will update if we hear more. [Update 8:52 a.m.: Microsoft would not confirm the figure, saying only: "We do not share financial details. Needless to say, we're very excited to bring VideoSurf to the Interactive Entertainment Business at Microsoft."]

TechCrunch Europe also notes that VideoSurf, founded in 2006, had raised $28 million from "a couple of tech heavyweights including Facebook COO Sheryl Sandberg and her husband, SurveyMonkey CEO David Goldberg, along with Al Gore and Current Media CEO Joel Hyatt and other investors, including Pitango VC and Verizon Ventures."

According to its website, VideoSurf uses "a unique combination of new computer vision and fast computation methods" that teaches "computers to 'see' inside videos to find content in a fast, efficient, and scalable way." The search is based on "visual identification, rather than text only," the website says.