Method and device for testing fisheye lens mtf

Abstract

An embodiment of the invention discloses a fish-eye lens MTF test method, which is characterized by calculating an optical center and radius of an effective light-emitting zone obtained when a sphere light source fisheye lens camera module shoots a sphere light source; according to the optical center and the radius, determining a detection zone in a preset field of view, the shape of the detection zone being determined according to position relation between the detection zone and the effective light-emitting zone; and finally, testing MTF of a fish-eye lens in the detection zone. The method prevents the phenomenon of MTF test inaccuracy caused by scene distortion due to distortion of the fish-eye lens, improves MTF test accuracy of the fish-eye lens, helps users to judge the imaging quality of the lens more accurately and visually, helps to improve camera quality detection accuracy and improves MTF test efficiency of the fish-eye lens. Besides, the embodiment of the invention also provides a corresponding realization device, thereby further enabling the method to have higher practicality. The device has the corresponding advantages above.

Description

technical field [0001] The embodiments of the present invention relate to the technical field of optical precision instruments, in particular to a method and device for testing the MTF of a fisheye lens. Background technique [0002] A fisheye lens is a wide-angle lens with a focal length of 16mm or less and a viewing angle close to or equal to 180°. In order to achieve the maximum photographic viewing angle of the lens, the front lens of this photographic lens has a short diameter and is parabolic to the front of the lens. protruding. The shorter the focal length, the larger the angle of view, and the stronger the distortion caused by the optical principle. The barrel distortion of the fisheye lens is larger, so that except for the scene in the center of the picture, other scenes that should be horizontal or vertical have occurred. Change accordingly. [0003] MTF (Modulation Transfer Function) is the numerical basis for analyzing the resolution of the lens. It is measure...

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Problems solved by technology

[0004] However, due to the large barrel distortion at the edge of the fisheye lens, using the ordinary MTF method (rectangular test frame) to test will cause the size of the MTF value to be inconsistent with the definition of the actual effect, which cannot objectively reflect the corresponding lens. image quality

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