Abstract
We apply the filter bank method, which extracts from a strongly defocused image the information on the amount of defocus, i.e., the information on the object distance, and simultaneously restores the object, to a defocused image of extremely low intensity, which is 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 the original object itself is simultaneously restored. The influence of the photon noise on the distance estimation is also quantitatively investigated. Then, the maximum likelihood-expectation maximization (ML-EM) method is adopted for image restoration, and the results are compared with those obtained by applying the conventional Wiener filter, It is experimentally shown that the ML-EM produces better image restoration than the Wiener filter in the extremely low intensity region where the maximal number of photons per pixel does not exceed about 450.
Original language | English |
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Pages (from-to) | 1024-1028 |
Number of pages | 5 |
Journal | Optical Engineering |
Volume | 42 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2003 Apr |
Keywords
- Image restoration
- Photon-limited imaging
- Range finding
- Semi-blind deconvolution
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics