Privacy of Facial Soft Biometrics: Suppressing Gender But Retaining Identity

We consider the problem of perturbing a face image in such a way that it cannot be used to ascertain soft biometric attributes such as age, gender and race, but can be used for automatic face recognition. Such an exercise is useful for extending different levels of privacy to a face image in a central database. In this work, we focus on masking the gender information in a face image with respect to an automated gender estimation scheme, while retaining its ability to be used by a face matcher. To facilitate this privacy-enhancing technique, the input face image is combined with another face image via a morphing scheme resulting in a mixed image. The mixing process can be used to progressively modify the input image such that its gender information is progressively suppressed; however, the modified images can still be used for recognition purposes if necessary. Preliminary experiments on the MUCT database suggest the potential of the scheme in imparting “differential privacy” to face images.