Precise localization of eye centers in low resolution color images

• Use of color information for accurately localizing eye centers.
• Statistical analysis of the color distribution of the skin, eye areas and irises.
• Radial symmetry computation both in grayscale images and in chrominance eye maps.
• We report high accuracy rates for low resolution color images.

The localization of eye centers and tracking of gaze constitutes an integral component of many human–computer interaction applications. A number of constraints including intrusiveness, mobility, robustness and high-price of eye tracking systems have hindered the way of the integration of eye trackers in everyday applications. Several ‘passive’ systems based on a single camera have been lately proposed in the literature, exhibiting though subordinate precision compared to the commercial, hardware-based eye tracking devices. In this paper we introduce an automatic, non-intrusive method for precise eye center localization in low resolution images, acquired from single low-cost cameras. To this end, the proposed system uses color information to derive a novel eye map that emphasizes the iris area and a radial symmetry transform which operates both on the original eye images and the eye map. The performance of the proposed method is extensively evaluated on four publicly available databases containing low resolution images and videos. Experimental results demonstrate great accuracy in challenging cases and resilience to pose and illumination variations, achieving significant improvement over existing methods.