As for the calibration board, many people do not know what it is for or why it is used. In fact, the role of calibration plate in image measurement, photogrammetry, 3D reconstruction and other applications is to correct lens distortion, determine the conversion relationship between physical dimensions and pixels, determine the relationship between the 3D geometric position of a point on the surface of a space object and its corresponding point in the image, and establish the geometric model of camera imaging. Do you know how the calibration board works? Here's a brief introduction:
Working principle of calibration plate:
Calibration plate is mainly used to correct lens distortion in machine vision, image measurement, photogrammetry and 3D reconstruction applications; Determine the conversion relationship between physical size and pixel; And determine the relationship between the three-dimensional geometric position of a point on the surface of the space object and the corresponding point in the image, and establish the geometric model of camera imaging.
The geometric model of the camera can be obtained through the calculation of the calibration algorithm after the camera takes a flat plate with a fixed spacing pattern array, thus obtaining high-precision measurement and reconstruction results. The flat plate with a pattern array with fixed spacing is the calibration plate.
To sum up, it is the working principle of the calibration plate. Through the calibration algorithm, the projection matrix of the camera can be calculated and the 3D measurement information of the scene can be provided. Without the absolute translation, rotation and scaling parameters of the real scene, the measure reconstruction at the level of similar transformation can be achieved. Therefore, under normal circumstances, the calibration board is usually used for machine vision system calibration, which greatly improves the detection and measurement accuracy indicators and effectively ensures that the machine vision system calibration can fully play its role in precision measurement and detection applications.
