Automatic extraction of pinna edges for binaural audio customization

The contribution of the external ear to the head-related transfer function (HRTF) heavily depends on the listener´s unique anthropometry. In particular, the shape of the most prominent contours of the pinna defines the frequency location of the HRTF spectral notches along the elevation of the sound source. This paper addresses the issue of automatically estimating the location of pinna edges starting from a set of pictures produced by a multi-flash imaging device. A basic image processing algorithm designed to obtain the principal edges and their distance from the ear canal entrance is described. The effectiveness of the developed hardware and software is preliminarily evaluated on a small number of test subjects.