Iris recognition using the Ridge Energy Direction (RED) algorithm

The authors present a new algorithm for iris recognition. Segmentation is based on local statistics, and after segmentation, the image is subjected to contrast-limited, adaptive histogram equalization. Feature extraction is then conducted using two directional filters (vertically and horizontally oriented). The presence (or absence) of ridges and their dominant directions are determined, based on maximum directional filter response. Templates are compared using fractional Hamming distance as a metric for a match/non match determination. This ridge-energy-direction (RED) algorithm reduces the effects of illumination, since only direction is used. Results are presented that utilize four iris databases, and some comparison of recognition performance against a Daugman-based algorithm is provided.