Fully automatic calibration method for high performance camera under complicated background

Abstract

With an object of solving problems existing in the prior art, the invention provides a fully automatic calibration method for a high performance camera under a complicated background. The method is combined with a Robust's checkerboard corner detection method, and two groups of checkerboards corners are adopted to serve as filters on the basis of the characteristics of the corners to filter marker images. Eight filters of two types are reduced to four filters of two types, which means that the wave processing amount halves and therefore, the calibration speed increases. Further, the method utilizes a Zhang's camera calibration method to mark the camera calibration parameters. The method utilizes the marked camera calibration parameters to standardize images to be corrected, and a normalized correlation of the standardized images is calculated, and then sub-pixel precision checkerboard corners are obtained. The method then re-projects the coordinate of the checkerboard corners onto image space to obtain a precise coordinate of the corner image. The newly obtained coordinate of the corners is then substituted into the Zhang's calibration method to obtain new computed camera parameters. By repeating the above steps, a performer can obtain highly precise camera parameters. According to the embodiments of the invention, it is possible for a performer to complete automatic corner detection and camera calibration without having to resort to human-machine interactive operations.

Description

technical field [0001] The invention belongs to the technical field of camera calibration, and in particular relates to a fully automatic calibration method for a high-performance camera. Background technique [0002] Phase camera calibration is one of the basic problems in computer vision, including calculating the internal and external parameters of the camera, and has important applications in the fields of object size measurement, 3D reconstruction, object recognition, robot navigation, etc. The calibration algorithm based on the pinhole camera model needs to establish a one-to-one correspondence between 3D object coordinates and 2D image coordinates, ie. The commonly used camera calibration algorithms include Tsai's two-step calibration method and Zhang's plate calibration method. Zhang's calibration method (seeing non-patent literature 1: ZhengyouZhang: AFlexibleNewTechniqueforCameraCalibration.IEEETrans.PatternAnal.Mach.Intell.(PAMI), 22(11):1330-1334, 2000.) Utilize...

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Problems solved by technology

In summary, so far there is no algorithm that can robustly detect checkerboard corners and calibrate the camera with high precision

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