An Online Camera Calibration Method Based on Blurred Images of Small Targets

Abstract

The present invention relates to an on-line camera calibration method based on the fuzzy image of a small target. Obtain an identifiable target image; establish a mathematical model of target feature point positioning uncertainty, and solve the positioning uncertainty of each feature point; take the target feature point positioning and parameter uncertainty as constraints, and use nonlinear optimization methods to solve the camera High-precision solution of internal and external parameters; this method does not need to consider the camera focus space and target size, and only needs a small high-precision target to be placed close to the lens to achieve ultra-high-precision camera calibration under conditions of large image blur and noise . The invention is suitable for on-line calibration of a camera with a large field of view and a shallow depth of field or even a camera in use, and has great flexibility and adaptability.

Description

technical field [0001] The invention relates to the technical field of sensor calibration, in particular to an online camera calibration method based on a small target fuzzy image. Background technique [0002] The camera is the most important core component in the field of computer vision, and camera calibration plays an important role in the computer vision system. Existing camera calibration methods require the target to be placed in the focal space of the camera to ensure a clear target image, and it needs to occupy a large area in the image. At the same time, the position of the target needs to have a large angle change, so that high-precision Camera calibration results. However, for large-field cameras represented by fisheye and catadioptric cameras, high-precision small and medium-sized targets in the camera’s focal space occupy a small area in the image, while large targets have low precision and are difficult to process. Placement is extremely inconvenient; for te...

AI Technical Summary

Problems solved by technology

However, the calibration methods based on these two types of targets are limited by the algorithm itself and have the disadvantage of insufficient calibration accuracy.

In addition, there are also many self-calibration techniques that do not require targets. These methods have the advantage of not using targets, and are widely used in video tracking, mobile robot visual navigation and other fields, but the calibration accuracy is average, and they are not suitable for applications that require high-precision camera calibration. occasion

[0004] However, in the existing main camera calibration methods, the target must be placed in the focus space, and the target size is required to be large enough. At the same time, the imaging is required to be clear and the feature point extraction is accurate, so as to achieve relatively high calibration accuracy.

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