In December 2009, when Google introduced Google Goggles, VP of engineering Vic Gundotra said that while the image recognition software could identify faces, the company had decided to delay implementing facial recognition to consider the privacy implications.
But Google continues to develop such technology and is exploring its potential as a search tool amid a broad effort to enhance its services with social networking capabilities.
A patent application filed in Europe last August and published on February 10, 2011, "Facial Recognition With Social Network Aiding," describes how the availability of social networking profile data can increase the accuracy of facial recognition.
The listed inventors, David Petrou, Andrew Rabinovich, and Adam Hartwig, have all worked on Google Goggles.
Coincidentally, the filing took place about a week before Google announced its acquisition of visual search engine Like.com.
The technique described in the patent application envisions checking visual queries against images accessible through social networking applications, calendar applications, and collaborative applications. Images obtained from these applications can then be compared for similarity to create a ranked list of possible identities to be used in conjunction with other search-related data.
Google's engineers have given some thought as to how to implement such technology while respecting user privacy. The patent application describes a scenario in which facial recognition capabilities might be made available only to the person positively identified in a picture. It also describes a permission-based scenario: "[O]nce the person is positively identified, a request is sent to that person asking [if he or she] will allow the image to be returned [as] a result for future queries for people within [his or her] social network."
The ideal of mining social network data to improve facial recognition is not Google's alone. Researchers at Harvard published a paper on this topic, "Autotagging Facebook: Social Network Context Improves Photo Annotation," in 2008.
Google did not immediately respond to a request for comment.
In general, patents and patent applications are not necessarily indicative of future products. But this particular one makes it clear that search is going social and is looking to input beyond text.