Eigenfaces Online Service

nordicfrost writes "At Norways largest online newspaper, they're doing the beta test of an Eigenface service. In short, it takes a portrait picture, treats it with some filters and analyzes the vectors in it. This is used for crimestopping and generic Big Brother activities. In this database, however, your mug is compared with celebrites to find which one that matches you the most. I match, among others, Brad Garrett. This site is pretty self-explaining, upload a portrait pic of yourself taken right in front of your face, closely cropped to the face and use the up arrow to see your top ten list of celebrity matches. You have to agree to some terms first, like giving permission to use your pic in promotions and other stuff and not to upload indecent stuff."

Comments

Avoiding recognition: Gaming the system

[G4from128k]

A facial recognition system like EigenFace looks for the dominant modes of variation among a population of faces to find predictors that help distinguish among the different faces. By ignore the ways that faces are more similar and accentuating the ways that faces are most different, they can craft identification algorithms. The only challenge is getting enough data to understand the full range of facial variations -- hence this solicitation for more facial data.

But I wonder if people can game this system to make themselves unrecognizable. For example, a member of the tin-foil hat brigade might submit multiple mugshots of themselves under mutliple assumed identities. By using slight variations in facial expression, makeup, lighting, and camera angle they would make the system think that a large fraction of the population "looks like" the person who seeks anonymity. The system would then have a hard time identifying the tin-foil hat wearer because he/she matches so many people in the test data.

Anyone can make themselves "look average" if they can bias the dataset that defines the average.