Pattern recognition correlator based on digital photo camera

Diffraction image correlator based on commercial digital SLR photo camera is described. The correlator is proposed for recognition of external 2-D and 3-D scenes illuminated by quasimonochromatic spatially incoherent light. Principal optical scheme of the correlator is analogous to that of incoherent holographic correlator by Lohmann. The correlator hardware consists of digital camera with attached optical correlation filter unit and control computer. No modifications have been introduced in units of commercial digital SLR photo camera. Digital camera was connected via camera interface to computer for controlled camera shooting, transfer of detected correlation signals and post-processing. Two ways were used for correlation filter unit mounting. In the first case, correlation filter was attached to the front of the camera lens. In the second one, it was placed in a free space of the SLR camera body between the interchangeable camera lens and the swing mirror. Computer generated Fourier holograms and kinoforms were used as correlation filters in experiments. The experimental setup of the correlator and experimental results on images recognition are presented. The recognition of test objects of direct and reversed contrast with the same correlation filter was performed.

[1]  A W Lohmann,et al.  Matched filtering with self-luminous objects. , 1968, Applied Optics.

[2]  Sudhakar Prasad,et al.  Engineering the pupil phase to improve image quality , 2003, SPIE Defense + Commercial Sensing.

[3]  Joseph van der Gracht,et al.  Information-optimized extended depth-of-field imaging systems , 2001, SPIE Defense + Commercial Sensing.

[4]  Reinhart Poprawe,et al.  Optical Information Processing , 1989 .

[5]  Edward R. Dowski,et al.  A New Paradigm for Imaging Systems , 2002, PICS.