Vision measurement calibration method based on circular target array and observation equation

Abstract

The invention discloses a vision measurement calibration method based on circular target array and observation equation. The method mainly comprises lab calibration and field calibration. In the lab calibration, intrinsic parameters, including horizontal scale factor, vertical scale factor, horizontal and vertical coordinates of the center of an image shot by a camera and radial distortion coefficient, of the camera are calculated based on a shot circular target array image. In the field calibration, obtained extrinsic parameters of the camera and an initial value of focal length are corrected based on an error correction equation; and accurate local length and extrinsic parameters, including camera azimuth angle, incline angle, rotation angle and photocenter coordinates, are calculated. In comparison with the prior art, the invention has advantages as follows: the intrinsic parameters of the camera only need to be calibrated once in a lab; and if pose of the camera changes, only the extrinsic parameters of the camera need to be measured once again and introduced into an error equation to be corrected so as to obtain a more accurate parameter value. The method provided by the invention is suitable for multiple calibrations; parameters which need to be calibrated are few; calculation amount is little; and operating speed is fast.

Description

technical field [0001] The invention relates to a visual measurement calibration method based on a circular target array and an observation equation, and belongs to the technical field of photogrammetry. Background technique [0002] The invention relates to a visual measurement calibration method based on a circular target array and an observation equation, and belongs to the technical field of photogrammetry. [0003] The objects of ocean hydrographic measurement include: sea temperature, salinity, ocean currents, tides, waves, transparency, water color, sea luminescence, sea ice, and ocean-atmosphere interactions. In recent years, the measurement of ocean waves has become one of the most important dynamic loads in the field of marine engineering, which has a great impact on the safety and cost of engineering structures. There are many ways to observe ocean waves: such as aerial wave measurement, stereo photography, planar homography, etc. However, the observation cost r...

AI Technical Summary

Problems solved by technology

Even with proper design, it is difficult to maintain stability in such a harsh environment

Once the camera position is changed, it needs to be re-calibrated, and there are many calibration parameters and a large amount of calculation

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