1. A method for determining HRTF, comprising: obtaining a plurality of reference images of different respective ears, the reference images associated with respective pre-determined HRTF information; obtaining an input image that includes an image of an ear of a subject; comparing the input image or information regarding the input image with the reference images or information regarding the reference images, using a processor, to obtain different respective results representing different respective degrees of match; and selecting one of the pre-determined HRTF information that corresponds with the one of the reference images providing the result representing the highest degree of match.