27 results about "Cardinal point" patented technology

The invention relates to the technical field of detection, in particular to a complex shell detection method and system based on structured light scanning. The method comprises the following steps: calculating a wrapped phase value and a phase modulation amplitude of each pixel point under each frequency, calculating discrete probability distribution containing candidate stripe series and a corresponding probability for each pixel point based on a multi-frequency wrapped phase difference, generating an initial pixel confidence map, and constructing an energy function; the penalty weight of the smooth item is determined according to the phase modulation amplitude and the wrapped phase gradient local variance, obtaining an initial fringe order distribution diagram, updating discrete probability distribution by using an initial pixel confidence map, re-minimizing an energy function to obtain a corrected fringe order distribution diagram, and reconstructing a final three-dimensional shape. And iteratively optimizing a projector principal point and a radial distortion coefficient in system calibration parameters. According to the scheme, the geometric details of the surface can be reserved, and the processing effect and the measurement precision of the complex curved surface and the high-curvature area are improved.

The invention relates to the technical field of data processing, and provides a target motion estimation method and device based on an optical flow method, and the method comprises the steps: collecting k continuous images corresponding to a to-be-detected target through an image collection device, and obtaining a to-be-detected target image set; determining optical flow field information of the to-be-detected target according to the to-be-detected target image in the to-be-detected target image set based on an optical flow method to obtain first optical flow field information; scene flow information of a to-be-detected target is determined according to equipment parameters of an image acquisition device and the first optical flow field information, first scene flow information is obtained, and the equipment parameters of the image acquisition device comprise the focal length and main point position information of the image acquisition device; and performing motion estimation on the to-be-detected target according to the first scene flow information to obtain a motion estimation result, so that the light flow information of the to-be-detected target can be adopted to perform motion estimation to obtain the motion estimation result, and the accuracy of determining the motion estimation result is improved.

The application discloses a kind of three-dimensional imaging method, system and computer readable storage medium based on multiple cameras.The method is applied to the three-dimensional imaging system including multiple cameras, comprising: using the three-dimensional imaging system of calibration takes target object;For the pixel point on the image that first camera takes, find the sub-pixel point on the image that other cameras take;For the pixel point on the image of first camera and the sub-pixel point on the image of other cameras, by normalization and distortion removal, obtain the projection point on the normalized imaging plane;For each group of projection points, from the principal point of each camera, multiple straight lines pointing to the projection point are drawn;For each group of straight lines, obtain the spatial point coordinates of the minimum Euclidean distance from each straight line in the group of straight lines in space, as the three-dimensional space coordinates of target object.The above-mentioned three-dimensional imaging method, system and computer readable storage medium can be more accurately positioned, improve the accuracy of three-dimensional reconstruction.

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 discloses a laboratory geometric distortion calibration method for large-aperture cameras, belonging to the field of aerospace optical remote sensor technology. The method first establishes a demonstration and verification environment for precise calibration of camera geometric distortion, with the target sphere of the laser tracker located at the infinity focal plane of the camera's main lens. The planar reflector is rotated multiple times within the full field of view of the camera's main lens. After each rotation, the target sphere is positioned at the infinity focal plane of the camera's main lens, and the current rotation angle of the planar reflector and the position of the target sphere are tested. Based on each rotation angle of the planar reflector and the position of the target sphere, the principal point, principal distance, and distortion of the camera's main lens are calculated. Through the application of this invention, high-precision calibration of the geometric distortion of large-aperture cameras is achieved.

The present invention provides a self-position estimation device and method that enable highly accurate self-position estimation of a camera without being affected by refraction errors caused by a light-transmitting part placed in front of the target. [Solution] The self-position estimation device 50 includes a self-position estimation unit 62 that estimates the self-position of the camera 20 based on an image taken by the camera 20 of a target group 16 in which a transparent window material 30 is placed in front of a plurality of targets 24; a line of sight detection unit 68 that detects a line of sight L from the principal point of the camera 20 toward the target 24 through the transparent window material 30 based on the self-position of the camera 20 estimated by the self-position estimation unit 62; and a correction unit 70 that corrects the self-position of the camera 20 based on the distance between the line of sight L and the target 24.

The application discloses a light center and principal point testing method, testing equipment and storage medium of a camera module. The light center and principal point testing method of the camera module comprises a light center test. The light center test comprises obtaining a calibration plate image. The calibration plate image comprises a plurality of color block patterns corresponding to color blocks on the calibration plate. A curved surface fitting algorithm is used to remove the color block patterns in the calibration plate image to obtain a light center test image. The middle region of the light center test image has a high gray value, and the surrounding region has a low gray value. A pixel point set with a gray value greater than a threshold Threshoc is selected to obtain a light center region. The center coordinates (OCx, OCy) of the light center region are calculated as the coordinates of the light center of the camera module. The calibration plate image is used for light center calculation, which is beneficial to avoid light center testing by an additional uniform light source, thereby simplifying the process of light center and principal point testing and improving the efficiency of light center and principal point testing.

The present application relates to the technical field of detection, and particularly relates to a complex shell detection method and system based on structured light scanning. The method comprises the following steps: calculating the wrapped phase value and phase modulation amplitude of each pixel point at each frequency, calculating the discrete probability distribution containing the candidate fringe order and the corresponding probability for each pixel point based on the multi-frequency wrapped phase difference, generating an initial pixel confidence map, constructing an energy function, determining the penalty weight of the smoothing term according to the phase modulation amplitude and the local variance of the wrapped phase gradient, obtaining a preliminary fringe order distribution map, updating the discrete probability distribution by using the initial pixel confidence map, re-minimizing the energy function to obtain a corrected fringe order distribution map, reconstructing the final three-dimensional topography, and iteratively optimizing the projector principal point and the radial distortion coefficient in the system calibration parameters. That is, the scheme of the present application can preserve the surface geometric details, improve the effect of processing the complex curved surface and the high-curvature area, and improve the measurement accuracy.

An anti-vibration mechanism for an imaging device is provided in an imaging device including a camera shake correction mechanism. Provided is an optical system which, in an imaging device provided with an optical system that moves in the direction of an optical axis and includes a focus adjustment mechanism, has an anti-vibration mechanism that performs camera shake correction by preventing vibration of an imaging element, and which, in order from the object side, is provided with an imaging lens group, an anti-vibration mechanism, and an imaging element on the anti-vibration mechanism. The image pickup element on the anti-vibration mechanism is rotated with respect to the optical axis of the image pickup lens group, and camera shake correction is performed.

The embodiment of the invention discloses a multi-lens camera calibration method and system and a storage medium, and is applied to the technical field of information processing. According to the initial camera parameters of the multi-lens camera, extracting a plurality of feature point sets in a matching space with overlapped images among all sub-lens panoramic images synchronously shot by a plurality of lenses of the multi-lens camera respectively, and determining three-dimensional space points corresponding to the plurality of feature point sets; in this way, when camera parameters are calibrated according to three-dimensional space points, the rotation and the position of the main lens in the multiple lenses are fixed, and two rounds of calibration are conducted on the image main points of the multiple lenses and the rotation of the auxiliary lens under the two conditions that the multiple lenses share the focal length or do not share the focal length. In this way, multiple rounds of calibration are carried out on part of camera parameters, under-fitting caused by too poor initial camera parameters can be reduced, and the situation that when the initial camera parameters are too far away from an ideal camera parameter combination, a loss function falls into a local optimal solution due to the fact that all the parameters are optimized at the same time is avoided.

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.

The invention relates to the technical field of attitude detection, in particular to a visual and spatial attitude alignment camera system, which comprises a focal length texture construction module, a guide pattern generation module, a boundary point location extraction module, a feature sequence screening module and an attitude line structure adjustment module. According to the method, the brightness jump direction and amplitude are obtained in the image focal length difference, the response structure is constructed in combination with the block directivity difference, the superposition range is limited through alignment of the brightness direction and the pattern, the boundary action area is extracted, interference points are eliminated according to the boundary direction and gradient consistency, and then a direction set is formed. And comparing an image inter-frame sequence order to screen a continuous principal point set, and combining a frame acquisition time change trend and a drift frequency compression matching window to integrally realize directional extraction of a weak edge structure in the image, spatial sequence stability verification and fine analysis of an attitude change rhythm. And the posture recognition precision under shielding interference and illumination variation is enhanced.

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 invention discloses a method and a device for calibrating a camera by observing a far target. The method comprises the following steps: S1, determining a principal point coordinate of the camera according to a characteristic that an image of a line segment coinciding with an optical axis on the camera is a principal point; s2, in combination with celestial body observation, acquiring real field angles of at least two remote targets relative to the optical center of the camera; s3, solving the focal length of the camera based on the principal point coordinates and the real field angle; and S4, gradually expanding from a distortion known region in the center of the pixel plane, and solving the full-pixel plane distortion characteristic of the camera. The required equipment is simple, and the cost is low; wherein the far target can be simulated by an optical method, so that the target identification degree is improved and the calibration field is reduced. The calibration process is carried out step by step, large-scale parameter optimization and falling into local minimum are avoided, and the reliability of the calibration result is improved.

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.

A method includes identifying a passthrough transformation associated with a VST XR device. The VST XR device includes see-through cameras that are (i) offset from forward axes extending from expected locations of a user's eyes and / or (ii) rotated such that optical axes of the see-through cameras are angled relative to the forward axes. The method also includes obtaining images captured using the see-through cameras, applying the passthrough transformation to the images to generate transformed images, and displaying the transformed images on one or more display panels of the VST XR device. The passthrough transformation is based on (i) a first transformation between see-through camera viewpoints and viewpoint-matched virtual camera viewpoints and (ii) a second transformation that aligns principal points of the see-through cameras and principal points of the one or more display panels.

The application discloses a depth and width estimation method based on binocular stereo vision and belongs to the field of computer vision. The method uses a binocular stereo camera to acquire images, establishes a mathematical model by using the relationship between the depth of an observation target distance imaging plane and the parallax and the relationship between the observation point's approximate width and the parallax, calibrates the depth and the width respectively, and thus provides a method for solving the real distance from the observation point to the principal point of the camera in a world coordinate system. The method also considers the error caused by the different principal points of the left and right cameras due to the camera installation problem, and improves the calculation precision of the depth and the width by fitting.

This invention discloses a method, apparatus, medium, and device for evaluating camera distortion correction effects. The method includes: performing affine transformation processing on a target object image after distortion removal, ensuring the target object is within the image range and that the feature points in the middle and edge portions of the processed target object image have consistent scales; detecting all feature points in the processed target object image and performing line fitting on feature points located on the same straight line to obtain the straight line containing each feature point; calculating the distance error from the feature point to the straight line containing the feature point for each feature point, and converting the distance error corresponding to the feature point into an angular error from the feature point to the principal point of the camera lens; and evaluating the distortion correction effect based on the angular errors corresponding to all feature points. This invention, by converting the straightness error from distance error to angular error, enables the use of a unified evaluation standard, thereby achieving a unified evaluation of the camera distortion correction effect.

A laser module includes first and second laser light sources emit first and second light, a first mirror, a second mirror, and first and second condensing optical systems provided between the first and second laser light sources and the first and second mirrors, in which radiation angles of the first light and the second light are the same, a distance between the first laser light source and a principal point of the first condensing optical system is greater than a distance between the second laser light source and a principal point of the second condensing optical system, an optical path length from the first laser light source to the second mirror is greater than an optical path length from the second laser light source to the second mirror, and a focal length of the first condensing optical system is greater than a focal length of the second condensing optical system.

The application provides a fisheye camera ranging method and a terminal. According to an image captured by a fisheye camera, a coordinate of a target point in a pixel coordinate system and a pre-calibrated coordinate of a principal point of the fisheye camera in the pixel coordinate system are obtained, and an imaging distortion coordinate of the target point in an imaging plane coordinate system is calculated. According to the imaging distortion coordinate of the target point in the imaging plane coordinate system, an imaging non-distortion coordinate of the target point in the imaging plane coordinate system is determined. The imaging non-distortion coordinate of the target point in the imaging plane coordinate system is converted into the pixel coordinate system to obtain a non-distortion target coordinate. According to the target coordinate, pre-calibrated internal parameters and external parameters of the fisheye camera, a coordinate value of the target point in a world coordinate system is solved. According to the coordinate value of the target point in the world coordinate system, a distance between a vehicle and the target point is determined. The application can improve the ranging accuracy of the fisheye camera.

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.

This invention provides a temperature compensation system for a depth camera, comprising a camera and a projector, and including the following modules: a relationship establishment module for storing a pre-set temperature compensation formula, which expresses the relationship between temperature and the principal point offset of the projector; a principal point calculation module for acquiring the temperature of the projector and determining the target principal point at that temperature based on the temperature compensation formula and the temperature; and a temperature compensation module for acquiring a structured light image captured by the camera at the specified temperature and generating a depth image or point cloud based on the target principal point and the structured light image. This invention can calculate the calibrated target principal point based on the actual operating temperature of the projector, thereby modifying the projector's intrinsic parameters to achieve temperature compensation for the depth camera, reducing errors in depth reconstruction, and expanding the working range of the depth camera.

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

A camera parameter calibration method, apparatus, processor, and vehicle are disclosed, relating to the field of image processing. The method includes: the processor acquiring an image sequence of a first scene using a first camera; calibrating the principal point parameters of the initial intrinsic parameters of the first camera based on the center points of at least two frames with different exposure parameters in the image sequence; addressing the issue that low image brightness and interference from vehicle-mounted structural components on the camera images can lead to poor image edge extraction accuracy during optical center calibration, resulting in poor optical center calibration accuracy and affecting the accuracy of principal point calibration; calibrating the principal points based on multiple frames of images with different exposures reduces the impact of low image brightness and interference from vehicle-mounted structural components on the principal point calibration, improving the accuracy of principal point calibration; then, the processor obtains the calibrated extrinsic parameters based on the calibrated intrinsic parameters and calibration board images, eliminating the need for production line intrinsic parameter calibration procedures requiring specific calibration scenarios, improving the site adaptability of camera parameter calibration, and reducing the operational complexity of camera parameter calibration.

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.