S. Ohno and S. Komatsu: Image Restoration and Object Distance Evaluation from a Defocused Photon Image, Proc. SPIE, Vol. 4416 (2001), 412-415.

Previously we developed the filter bank method that enables to extract from a defocused image the information on the amount of defocus. In this paper, we apply this method to a defocused image with extremely low intensity detectable only with a photon counting camera. Experimental results show that the information of the defocus amount can be extracted from such a blurred photon image and simultaneously the original object is successfully restored.