9 results about "Cardinal point" patented technology

The application provides a high-precision calibration method, device and equipment for mapping camera interior orientation elements and a storage medium. The method comprises the following steps: firstly, using a collimator and an electronic theodolite to independently calibrate the rotary table angle positioning error and the parallel light tube optical axis pointing deviation, respectively, to generate an error correction model and a space angle matrix, and converting the device system error into a known quantity that can be compensated; secondly, using a positive and negative mirror center-finding method to iteratively converge to determine the accurate intersection point of the sight axis and the target surface as the main point initial observation value and the sight axis reference angle, and eliminating the uncertainty of the main point; finally, starting from the reference angle to perform full field scanning and collection, and jointly substituting the corrected angle data, the angle matrix and the main point observation value into the collinearity condition equation for overall adjustment solution, so that the interior orientation elements and the distortion parameters purely reflecting the characteristics of the camera itself are solved under the premise that various system errors have been stripped one by one.

This invention discloses a method for extrinsic parameter calibration between a camera and a lidar based on the vanishing point method, comprising the following steps: S1, acquiring an optical image of a target reference object using a camera, and acquiring laser point cloud data of the target reference object using a lidar; S2, determining the principal point and focal length of the camera based on the optical image; S3, processing the laser point cloud data based on the determined principal point and focal length of the camera to obtain a lidar projection image; S4, calibrating the extrinsic parameters between the camera and the lidar using the vanishing points of the optical image and the lidar projection image, and obtaining the extrinsic parameter calibration results; S5, further optimizing the camera's principal point, focal length, and extrinsic parameter calibration results using an iterative optimization method to obtain optimized extrinsic parameter calibration results. This invention utilizes vanishing points to solve the extrinsic parameter calibration problem between a camera and a lidar in scenarios without a calibration board, improving the efficiency and accuracy of extrinsic parameter calibration between lidar and camera.

This invention provides a thermal drift compensation method and system for a 3D structured light camera. It uses fixed physical markers within the scene to provide a reference ground truth, monitors and quantifies the scan amplitude contraction and static origin drift caused by galvanometer thermal drift in real time, calculates the deviation between the current wrapped phase and the reference phase, and performs forced phase alignment compensation across the entire field to avoid misjudgment of multi-frequency heterodyne unwrapping order. It dynamically reconstructs the projector intrinsic parameter matrix, uses the scaling factor s and translation vector t to correct the equivalent focal length and principal point coordinates in real time, and uses the calibration plate depth residual for closed-loop iterative optimization. This invention does not rely on a temperature model, effectively eliminates thermal hysteresis, ensures the stability of phase unwrapping and the geometric accuracy of 3D reconstruction across the entire temperature range, and is ready to use upon startup. It overcomes the shortcomings of traditional open-loop temperature compensation, and compensates for thermal drift errors in real time through closed-loop feedback, improving the stability and accuracy of 3D reconstruction in the structured light system.

This eliminates the need to acquire pattern images from multiple viewpoints to obtain the camera's optical parameters, improving robustness against shifts in shooting position. [Solution] A camera calibration method that acquires a pattern image obtained by photographing calibration boards 30 and 32, each equipped with two spaced-apart pattern boards, using cameras 10, 12, and 14; obtains principal point coordinates indicating the position of the lens optical axis on the image sensor based on the patterns displayed on the two pattern boards captured in the pattern image; and uses the principal point coordinates and the relative positional relationship between cameras 10, 12, and 14 and the calibration boards 30 and 32 to acquire optical parameters other than the principal point coordinates, including the focal length, based on the pattern image.

The application provides a distortion correction method and device, electronic equipment and storage medium, wherein the method comprises: determining actual coordinates corresponding to a plurality of calibration points according to target images obtained by photographing the plurality of calibration points by a target camera; determining principal point coordinates and focal length of the target camera according to the actual coordinates corresponding to the plurality of calibration points; constructing a mixed effect model of the target camera based on the actual coordinates corresponding to the plurality of calibration points, the principal point coordinates and the focal length of the target camera, wherein the mixed effect model comprises a fixed effect model and a random effect model; and performing distortion correction on an imaging area of the target camera through the mixed effect model. The mixed effect model constructed by the application can capture global trends of distortion and correct local residual distortion, thereby achieving high-precision correction of full-field distortion, improving adaptability and robustness of distortion characteristics of different cameras, and being able to adapt to significant differences in regional distortion of large-field cameras.

The application discloses a virtual light source information determination method and device for line-of-sight tracking, equipment and a storage medium, the method is applied to a line-of-sight estimation system, the line-of-sight estimation system comprises a real light source and a plurality of cameras, and the method comprises the following steps: determining the position of a preset virtual light source in a three-dimensional space; determining a plane that passes through the principal point of the camera and is parallel to a first straight line that passes through the real light source and the virtual light source as a virtual camera plane of the camera; mapping a real light spot image point formed by the real light source on a real image plane of the camera to the virtual camera plane to obtain a first mapping point corresponding to the real light source on the virtual camera plane; based on the first mapping point, a second mapping point corresponding to the virtual light source on the virtual camera plane is calculated; and the second mapping point is reversely mapped to the real image plane to obtain a virtual light spot image point formed by the virtual light source on the real image plane.

An image capturing optical system includes seven lens elements (E1, E2, E3, E4, E5, E6, E7). In a first embodiment E3 has negative refractive power, the object-side surface of E5 is concave in a para

Disclosed is a camera calibration method that eliminates the need to acquire pattern images from multiple viewpoints in order to acquire optical parameters of a camera, and that improves robustness with respect to imaging position deviation. The disclosed calibration method includes: acquiring pattern images obtained by using cameras 10, 12, 14 to image calibration boards 30, 32 comprising two pattern boards disposed spaced apart from each other; acquiring principal point coordinates indicating the position of a lens optical axis on an imaging element on the basis of patterns displayed on the two pattern boards captured in the pattern images; and using the principal point coordinates and relative positional relationships between the cameras 10, 12, 14 and the calibration boards 30, 32 to acquire optical parameters including the focal length and not including the principal point coordinates, on the basis of the pattern images.

The application relates to the technical field of image processing, and particularly discloses a single-lens multi-sensor joint calibration and splicing method based on a co-pose constraint, which comprises the following steps: extracting corner point features in each sub-image, and identifying the identity index of the corner point features on a composite calibration board; establishing a unified imaging geometric model, performing two-stage joint calibration based on the unified imaging geometric model, and the optimization target of the two-stage joint calibration comprises: single field of view reprojection error minimization of each sub-image, and projection consistency constraint between adjacent sub-sensors; determining the relative positions of the sub-images in a global splicing canvas according to the principal point parameters in the solved intrinsic parameters, and splicing a panoramic image. The application establishes a unified imaging model with a co-pose constraint, simultaneously introduces single field of view reprojection and overlapping field of view projection consistency constraints in calibration, makes the multi-sensor system form a unified geometric reference, and significantly reduces the misplacement and ghosting of a splicing boundary.