Camera lens point spread function measurement method based on single pixel imaging

Abstract

The invention relates to a camera lens point spread function (PSF) measurement method based on single pixel imaging and can effectively improve the signal to noise ratio of PSF measurement while PSF measurement of the full field of view space variation is realized. Before measurement, firstly, a liquid crystal display (LCD) is vertically placed along an optical axis of a camera; during measurement, firstly, a base image mode required for single pixel imaging is displayed on the liquid crystal display, and the camera is utilized to take a picture; secondly, according to the single pixel imagingprinciple, an optical transmission coefficient from each point on the liquid crystal display to a single pixel on the camera image is calculated; single pixel imaging is performed on all the pixels on the camera image to obtain optical transmission coefficients of all the points on the LCD to all the pixels on the camera image; and lastly, based on the optical transmission coefficients of all thepixels on the camera image, the point spread function from any point on the liquid crystal display to the camera image is calculated. The method is advantaged in that the camera lens point spread function PSF measurement result with the higher signal-to-noise ratio than a traditional star point method can be obtained under the same camera exposure time.

Description

technical field [0001] The invention relates to a method for measuring the point spread function of a camera lens based on single-pixel imaging, which improves the signal-to-noise ratio of the PSF measurement of the point spread function and realizes spatially varying PSF measurement. The present invention is in the field of computational imaging. Background technique [0002] The point spread function PSF mainly characterizes the luminance distribution formed by the point light source passing through the optical system, and it is an important parameter to describe the image blur caused by factors such as optical system aberration and defocus in the imaging process. It can better reflect the performance of the camera lens, and it is also the basis for image restoration. [0003] Most of the existing PSF measurement methods regard the PSF model as a symmetrical and space-invariant model, so it has a certain degree of limitation and is only applicable to some imaging systems....

AI Technical Summary

Problems solved by technology

The method of directly using a point light source to measure PSF can theoretically obtain the point spread function of the entire field of view by changing the spatial position of the point light source, but ordinary point light sources cannot accurately measure PSF due to the low signal-to-noise ratio. However, it is difficult to change the imaging position of the point light source by using a laser to generate a point light source, and it is impossible to measure the spatially varying PSF.

Therefore, how to solve the problem of incompatibility between high signal-to-noise ratio and spatial variation measurement has become the key to spatial variation PSF measurement

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