Distortion compensation method based on wide-angle lens

Abstract

The invention discloses a technology which realizes distortion compensation by using triple smoothing spline curve to perform modeling and compensating on barrel distortion caused by a wide-angle lens, comprising the following steps: 1) manufacturing a concentric-circle template, and making a cross at the center of the concentric circle; 2) aligning and shooting the concentric-circle template image to obtain the ideal radius value and the actual-measurement radius value of the template; 3) according to two groups of radius values, using a natural spline curve to construct a forward spline curve and a backward spline curve; 4) using the forward spline curve to calculate and restore the size of the image, using the backward spline curve, and establishing a distortion compensation mapping table; and 5) according to the mapping table, using bilinear interpolation algorithm to calculate and realize distortion compensation. The invention has a plurality of criteria points to calculate the radius of the concentric circle, so that the invention has high radius calculation precision and strong anti-noise capability; the invention adopts the spline curve to model and compensate barrel distortion and has simple and reliable calculation; according to modeling results, the invention manufactures a distortion compensation mapping table to realize efficient and effective distortion compensation in real time.

Description

technical field [0001] The invention relates to an efficient and real-time distortion compensation method based on a wide-angle lens. Specifically, it relates to a technique for modeling and compensating barrel distortion caused by a wide-angle lens by using a cubic smooth spline curve to achieve distortion compensation. Background technique [0002] Due to its wide viewing angle and special shooting effects, wide-angle lenses are widely used in photography, monitoring, measurement, and medical fields, such as clinical endoscopes and supermarket anti-theft monitoring systems. If it is equipped with a lens with a short focal length, the use of a wide-angle lens can usually obtain the entire image of the target object while reducing the height of the device, which will be very conducive to the miniaturization and portability of the device, and at the same time reduce the cost of the device. The latter is because in the case of the same height and focal length, to achieve the s...

AI Technical Summary

Problems solved by technology

[0003] Wide-angle lens not only obtains a wide field of view, but also produces serious geometric distortion to the final imaging image - barrel distortion

Image distortion brings difficulties to feature extraction and parameter calculation, especially in the monitoring field. Image distortion will also cause the monitor to be unable to clearly judge the imaging object, which is more obvious when the imaging distortion is serious.

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