Stereo coding target for calibrating internal parameter and distortion coefficient of camera and calibration method thereof

Abstract

The invention discloses a stereo coding target for calibrating an internal parameter and a distortion coefficient of a camera and a calibration method thereof. The stereo coding target is formed by four flat plates at a certain angle, the flat plates are provided with same circular characteristic pattern arrays, and the center of mass thereof is a to-be-extracted mark pint; and connecting positions of the flat plates in the vertical direction are provided with two quadrangular coding patterns used for coding of the four flat plates. The calibration method includes: firstly photographing a stereo coding target image; and extracting circular characteristic patterns in the image and the coordinate of the center of mass of the quadrangular coding patterns, wherein the quadrangular coding patterns are used for coding of the four flat plates, and the image coordinate and the physical coordinate of the center of mass of the circular characteristic patterns are used for calculating the internal parameter and the distortion coefficient of the camera. Compared with the prior art, according to the stereo coding target and the calibration method thereof, only one stereo coding target image needs to be photographed, the requirement of the depth of field of a camera lens is not high, the stereo coding target and the calibration method thereof are applicable to calibration of a multi-camera system, the mark points in different flat plates can be rapidly distinguished, the calibration process is simple, and the precision is high.

Description

technical field [0001] The invention relates to the technical field of camera calibration, in particular to a stereo coding target for calibrating camera internal parameters and distortion coefficients and a calibration method thereof. Background technique [0002] Photogrammetry technology is widely used in modern life and industrial measurement. Camera calibration technology is a key step in photogrammetry technology. The quality of calibration is directly related to the reliability of measurement results. According to the characteristics of the measurement object, the selected camera performance, number and arrangement of the camera array. At present, surface reconstruction of large-scale objects and three-dimensional modeling of three-dimensional objects have become the main hot issues. Improving the accuracy of calibration results and simplifying the calibration process have become the key technologies for multi-camera calibration. Existing calibration targets can be m...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a stereo coding target and its calibration method for calibrating the internal parameters and distortion coefficients of the camera, so as to solve the problem of the error influence caused by the inaccurate extraction of feature corners on the image due to inaccurate focusing in the prior art

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