Google has acquired, a start-up that uses visual search technology to help shoppers find, for example, black high-waisted trousers or red sandals without knowing a specific designer.

Six-year-old also includes shopping personalization engine, a visual styling tool called Couturious, and What to Wear, a recently launched fashion Q&A site.

The price was not disclosed, though TechCrunch – which first revealed the acquisition -- puts the figure at around $100 million. Google first flirted with the San Mateo, California-based company in 2005, when it was called Riya and focused on image facial recognition, but eventually walked away. emerged from Riya's ashes, raising nearly $50 million in venture capital since 2006. It has revenues of some $50 million per year. is Google's 24th acquisition this year and its third this month. Google already has its own picture-matching function (click "Find similar images" on a Google image search) but combining it with's could help bring about a world where people snap cell-phone pictures of products they want and are brought to a website to buy them.

Google has long been interested in visual technology. In 2008, two Google scientists at an international conference described their work on VisualRank, which blends image-recognition software methods with techniques for weighting and ranking similar images. This cuts down on duplicates and "image spam," a.k.a. inappropriately tagged photos, but it doesn't improve the search engine's ability to identify people.

"We're pleased and excited to welcome to Google, where they'll work closely with our commerce team," said Andrew Pederson, a Google spokesman.

"We were the first to bring visual search to shopping, the first to build an automated cross-matching system for clothing, and more," CEO Munjal Shah, who co-founded the company, said in a message on's website. "We didn't stop there, and we don't have plans to stop now. We see joining Google as a way to supercharge our vision and supercharge our passion."

Shah previously was co-founder and CEO of Andale, which provides software to eBay merchants.