2007 年 12 巻 1 号 p. 27-34
Images of the ear are highly valuable for facial photographic identification because the ear has a lot of morphological features, such as the helix, ear lobe, antihelix, scapha, antitragus, tragus, and so on. However, the morphology of ear components changes so easily depending on the camera angle that it is usually difficult to identify people based on images of their ears from surveillance cameras and mug shots.
In this study, the correlation between the morphology of ear components and camera angles was investigated in order to identify people based on ear images taken from different camera angles. The samples were ear images of 56 persons taken at 27 different camera angles for each person. The morphologies of the ear components were compared among the angles and among the subjects. This revealed the morphological changes in the helix, ear lobe, antihelix, and tragus according to the camera angle.
It was found that the morphology was consistent between ear images taken at different camera angles if the compared images satisfied two conditions: the scapha must be clearly observed, and the external acoustic meatus must not be visible. If these conditions are met, it is possible to identify a person by images of his or her ear regardless of the camera angles.