Abstract:

 The authors proposed a power spectrum autofocusing method based on defocus iris images. Firstly, we gave the relation curve  between autofocusing evaluation function value PS and blur radius of each iris image. Experiments show that the power spectrum evaluation function could find the location of system focusing mirror when the image is clearest. Moreover, we dealt with evaluation function curve by means of Gaussian fitting, and the relation number of the curve could reach 0.994 7(close to 1),  verifying the accuracy of the power spectrum autofocusing evaluation function.

Key words: defocus blurred iris image, power spectrum, autofocusing evaluation function