Image shift detecting and imaging system based on optical joint transform correlator

Abstract

The invention relates to an image shift detecting and imaging system based on an optical joint transform correlator. The system comprises laser parallel light tubes, an amplitude modulation transmission type spatial light modulator, a phase modulation reflection type spatial light modulator, a Fourier transform lens and a CCD (Charge Coupled Device) camera. The laser parallel light tubes, the amplitude modulation transmission type spatial light modulator and the phase modulation reflection type spatial light modulator are arranged on the same optical path in turn. The Fourier transform lens is arranged on a reflective optical path of the phase modulation reflection type spatial light modulator. The CCD camera and the Fourier transform lens are arranged on the same optical path. The invention provides an image shift detecting and imaging system based on the optical joint transform correlator. The system is used for eliminating the sensitivity of the system to defocus and increasing image shift detection stability.

Description

technical field [0001] The invention belongs to the field of optics, and relates to an imaging system, in particular to an image motion detection imaging system based on an optical joint transform correlator. Background technique [0002] During the imaging exposure time, if there is relative motion between the target and the camera, the final image will be blurred and degraded. There are two ways to eliminate the impact of motion blur on image quality: one is to use digital image restoration algorithms to remove motion blur and restore image information through deconvolution; the other is to rely on specific hardware to compensate for imaging in real time The image movement generated during the exposure time, so as to achieve the purpose of stable imaging. [0003] Regardless of the method used, accurate detection of image motion is crucial, because image motion detection can improve the accuracy of image restoration for software compensation methods, and is a critical fir...

AI Technical Summary

Problems solved by technology

[0016] JTC-based image motion detection has strong environmental adaptability and can be applied to situations with extremely low signal-to-noise ratios, but once it involves CCD camera imaging, defocus is an unavoidable problem

[0017] Improper installation or excessive vibration will cause the CCD camera to defocus when receiving the jointly transformed power spectrum and cross-correlation peak images

Defocus will reduce the signal-to-noise ratio of cross-correlation images, which will affect the accuracy of centroid extraction, and then affect the stability of image motion detection

When the system is in focus, the obtained cross-correlation peak is very obvious. Once it is out of focus, many false sub-peaks will be generated in the background, which will interfere with the position of the real cross-correlation peak.

[0018] Traditional JTC has two CCD imaging processes, so it may introduce defocus twice

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