Colored planar array camera MTF (Modulation Transfer Function) testing method and device

Abstract

The invention provides a colored planar array camera MTF (Modulation Transfer Function) testing method and a colored planar array camera MTF testing device. The colored planar array camera MTF testingmethod comprises the following steps: calibrating three color channels RGB of a colored planar array camera based on the linear response characteristics of a detector, and acquiring a correction coefficient for all photosensitive points of the three color channels RGB on a color area array by using an integrating sphere or another standard uniform surface light source, wherein the correction coefficient is a correction coefficient required by a pseudo-spectral radiation balance method; performing pseudo-spectral radiation balance correction on spectral radiation response of the colored planararray camera by using the obtained correction coefficient to obtain a corrected image; according to the corrected image, performing colored planar array camera MTF testing by one or more MTF testingmethods of an edge method, a star point method and a periodic rectangular target method. Gray correction is performed on a colored RGB image by the pseudo-spectral radiation balance method, so that the conventional MTF testing method can be applied to MTF testing of the colored planar array camera.

Description

technical field [0001] The invention relates to the technical field of color cameras, in particular to a color area array camera MTF testing method and device. Background technique [0002] Camera MTF (Modulation Transfer Function) is a function of the camera imaging contrast with respect to the spatial sampling frequency. The function value is the ratio of the image space contrast to the object space contrast, which reflects the modulation characteristics of the camera for the light and dark information of the object space, and is an objective quantification of the camera imaging quality. evaluation indicators. Especially for the entire imaging system of the camera, the MTF value corresponding to the Nyquist frequency of the imaging system is the most representative. Certain industries will directly use the MTF value corresponding to the Nyquist frequency instead of MTF to evaluate the imaging quality of the camera. [0003] There are many camera MTF testing methods. Accor...

AI Technical Summary

Problems solved by technology

However, based on the MTF obtained through function fitting and Fourier transform based on discrete data sampling, the data processing chain is long, and the small changes in the original data have a huge impact on the final calculation results, data validity, reliability and test repeatability Not high, the test results are not intuitive enough, lack of periodic rectangular target method results as a reference, therefore, the test results are not very convincing

[0011] Therefore, the MTF test of the color area scan camera has very limited test methods. The edge method is often questioned due to its complex data processing and the lack of other test results for reference.

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