An improved multiscale retinex algorithm for motion-blurred iris images to minimize the intra-individual variations

Motion-blurred iris image is caused by less user cooperation, poor quality cameras and environmental conditions when capturing image, thus contributing to a variety of iris patterns, which are due to the shadows and noises occurring in the image. The biggest challenge dealing with motion-blurred iris image is to analyze the exact pattern of the iris image. The combination of homomorphic filtering and multiscale retinex algorithms can cope with the illumination changes and shadow removal in order to produce enhanced iris pattern. Homomorphic filtering is applied to remove shadows on motion-blurred image. The processed image that is free of shadows is then applied with multiscale retinex algorithm to improve the contrast of the image. The enhanced iris pattern that is free of shadows is then evaluated using intensity histogram to validate the proposed method. The accuracy of the proposed method is 99.2% with minimum false rejection and false acceptance rate. (C) 2013 Elsevier B.V. All rights reserved.