64 results about "Projector calibration" patented technology

A system determines correspondence between locations on a display surface and pixels in an output image of a projector. The display surface can have an arbitrary shape and pose. Locations with know coordinates are identified on the display surface. Each location is optically coupled to a photo sensor by an optical fiber installed in a throughhole in the surface. Known calibration patterns are projected, while sensing directly an intensity of light at each location for each calibration pattern. The intensities are used to determine correspondences between the of locations and pixels in an output image of the projector so that projected images can warped to conform to the display surface.

A stereo-phase-based absolute three-dimensional (3D) shape measurement method is provided that requires neither phase unwrapping nor projector calibration. This proposed method can be divided into two steps: (1) obtain a coarse disparity map from the quality map; and (2) refine the disparity map using local phase information. Experiments demonstrated that the proposed method could achieve high-quality 3D measurement even with extremely low-quality fringe patterns. The method is particular well-suited for a number of different applications including in mobile devices such as phones.

It is the general calibration method of model-surface optical measuring system. Calibration board on which is located evenly with black rhombic square array in the white background and projector calibration grating of corresponding rhombic square array are uniquely employed in this invention. The calibration board position is corrected by laser to make the projector to project rhombic square array into the white interstice on the calibration board whose images before and after shutting up the projector is recorded by the camera used as calibration image. Then the basic data are obtained through the processing of the calibration image and accordingly the space coordinates of the projector calibration dots can be calculated. The calibration of the projector is realized on the basic datum through matching the coordinates of corresponding calibration dots of projector image. According to the relationship between the coordinate systems of projector and camera the calibration of systematic geometric parameter can be realized. The invention is of great engineering utility and can solve the accuracy problem of automatic extraction and realize the integrated calibration of camera and projector.

The invention belongs to the field of three-dimensional reconstruction technology, and relates to a three-dimensional reconstruction method. The three-dimensional reconstruction method is combined with binocular stereo vision technology, structured light technology and rotating platform technology and has advantages of high precision, high speed and low cost. Compared with binocular stereo vision, the three-dimensional reconstruction method has advantages of higher reconstruction speed, higher precision and high effect to an area without abundant object surface patterns. Compared with traditional structured light technology, a system according to the three-dimensional reconstruction method is advantageous in that a trouble in projector calibration is not required; a second camera replaces a projector; accuracy in camera calibration is higher than accuracy in projector calibration; and better reconstructed three-dimensional point cloud is realized. A rotating platform splicing algorithm is utilized in multi-visual-angle point cloud splicing. Compared with a traditional ICP registration method, the three-dimensional reconstruction method has advantages of higher point cloud splicing speed, no requirement for initial point cloud data, simple operation and no requirement for artificial participation.

The invention discloses an automatic calibration method for a three-dimensional structured light scanner system, which comprises the following steps: 1, setting a calibration object; 2, shooting a plurality of calibration photos of the calibration object with different postures by using a camera, and shooting calibration pictures; 3, initially recognizing points on the calibration photos to obtain a candidate region of each angular point, and then initially recognizing the angular points; 4, solving sub-pixel coordinates of the angular points in the candidate region; 5, determining the sequence of the angular points; 6, adopting a Zhengyou Zhang algorithm to calibrate camera parameters; 7, processing projector calibration photos; and 8, solving three-dimensional coordinates of inner parameters inversely by utilizing the inner parameters of the camera obtained by the step 6, wherein the three-dimensional coordinates correspond to the coordinates of the angular points in the calibration pictures one by one, and adopting the Zhengyou Zhang algorithm to calibrate a projector. The invention provides an automatic calibration method for a structured light scanner, the automatic calibration can be completed once, and the calibrated parameters have high accuracy.

There is provided an image projection device including a camera, a projector configured to project an image, a camera calibration unit configured to perform calibration of the camera, a projector calibration unit configured to perform calibration of the projector, and an image correction unit configured to correct the image projected from the projector based on a result of the calibration. The projector calibration unit performs ray tracing of a known checker pattern on which structural light is projected by the projector, and estimates parameters by acquiring correspondence relation between a lattice point of the checker pattern and projector coordinates.

The invention relates to free multi-viewpoint multi-projection three-dimensional display system and method. The system includes one to five videotape color CCD video cameras, one calibration color CCD video camera, two to eight projectors, one large screen display terminal, one calibration plate, and the compute set multi-path synchronization image acquisition card by which it is connected with the video camera, and multi-path output display card by which it is connected with the projector. The method includes the steps that image source video frequency coding, projector calibration, stereo image mosaicking. The invention can realize large screen vivid three-dimensional multi-projection display based on computer vision technology.

The invention discloses a projector area calibration method by utilizing concentric circular rings on the basis of a lens distortion rule, and solves a problem of low calibration precision when a field of view is enlarged at present while a problem of insufficient optical lens distortion processing is solved. The method comprises the following steps: firstly, projecting a specially-designed checkerboard image onto a plane calibration board by utilizing a DLP (Digital Light Processing) projector, and capturing a calibration object image which contains a pasting checkerboard and a projection checkerboard by a CCD (Charge Coupled Device) camera; changing the position of the plane calibration board for multiple times to obtain multiple pairs of calibration object images; according to the lens distortion rule, taking the center of each calibration image as a center of a circle, calculating distance between each angle point to the center of a circle, and comparing the distance with a given radius value to divide the concentric circular ring areas; on the basis of each concentric circular ring, calibrating a camera, carrying out distortion correction to the data of the projection checkerboard by utilizing calibration parameters so as to calibrate the projector to obtain the internal and external parameters of the projector of a corresponding area; and repeating the above operations to the circular ring areas to finish the calibration of the projector.

A system and method are disclosed for calibrating a plurality of projectors for three-dimensional scene reconstruction. The system includes a plurality of projectors and at least one camera, a camera-projector calibration module and a projector-projector calibration module. The camera-projector calibration module is configured to calibrate a first projector with the camera and generate a first camera-projector calibration data using camera-projector duality. The camera-projector calibration module is also configured to calibrate a second projector with the camera and generate a second camera-projector calibration data. The projector-projector calibration module is configured to calibrate the first and the second projector using the first and the second camera-projector calibration data.

Embodiments of the invention describe apparatuses, systems and methods for dynamic projector calibration. Embodiments of the invention execute operations for capturing, via an image sensor included in a projector device, image data of an area around the projector device. Said image sensor captures 3D distance information as well as image pixel information of the surrounding area. A projection area is selected based (in part) on surface properties of the projection area determined from the image data.The projector may be calibrated (e.g., projection brightness, color balance, angle, etc.) based on the captured image data. A user I / O interface is projected onto the selected projection area, and the projector may be further (i.e., dynamically) calibrated based on captured image data of the projected user I / O interface.

The invention relates to a projector calibration method based on a red and blue checkerboard calibration plate. The method comprises the steps that the calibration plate is selected; a measurement system is set up; a corner point coordinate is extracted; deformation grating fringe images are collected; a filtering function is constructed for compensation, wherein Fourier transforming is carried out on the acquired deformation grating fringe images in horizontal and vertical directions to acquire the amplitude spectrum image of deformation grating stripes; a frequency domain filtering function is constructed for filtering to extract fundamental frequency component and direct current component in the amplitude spectrum image; inverse Fourier transforming is carried out on the extracted fundamental frequency component and direct current component to acquire compensated deformation grating fringe images in horizontal and vertical directions; the wrapped phase images of the compensated deformation grating fringe images in horizontal and vertical directions are calculated; a target image is acquired after dephasing; and a projector is calibrated. According to the invention, the constructed frequency domain filtering function can filter out components except the fundamental frequency component and the direct current component; and the influence of gamma nonlinearity and environmental noise can be obviously reduced.

The invention discloses a three-dimensional measurement method based on improved multi-frequency stripe structured light. The method is characterized by comprising the following steps of 1, generatingmulti-frequency coded stripe images; 2, conducting camera calibration; 3, conducting projector calibration; 4, projecting the coded stripe images and calculating an absolute phase of a stripe image the frequency of which is fn; 5, conducting three-dimensional reconstruction measurement. According to the method, applied equipment is simple, the cost is low, and precise three-dimensional measurement can be carried out on the surfaces of large objects complex in profile and drastic in transition.

The invention discloses a rapid projector system parameter calibration method. The rapid projector system parameter calibration method comprises that 1) camera calibration parameters are calculated by means of a Zhengyou Zhang camera calibration method; 2) a plane equality of the plane where a calibration board is arranged in a camera coordinate space is calculated; 3) a projector projects a projection calibration feature image on the plane where the calibration board is arranged, a camera captures the projection calibration feature image, and the three-dimensional coordinate of the projection calibration feature image is calculated by means of a crossing algorithm of projection light beams and the calibration plane; 4) internal calibration parameters of the projector are calculated by means of an optimized least square method, and therefore a coordinate mapping relation among the camera imaging space, the space where the projection display surface is arranged and the projector projection image space is calculated. According to the invention, by means of the crossing principle of the projection light beams and the calibration plane, the camera calibration and the projector calibration can be calculated in unified manner, and a rapid system calibration method which has robustness is provided for the calibration calculation of internal parameters and external parameters of the projector.

The present disclosure relates to a method for calibrating a projector. The method includes projecting a test pattern onto a scene or an object within the scene and capturing the test pattern using a camera. Once the test pattern image has been captured by the camera, the method further includes estimating by a processing element a perspective projection matrix, warping the estimated projection matrix based on a non-linear distortion function, and modifying the projector to project light based on the distortion function. The present disclosure also relates to a presentation or projection system including two types of projectors for projecting an output presentation having a second image overlaid on a first image.

The invention relates to a quick three-dimensional shape measurement method without phase unwrapping based on Fourier transform, and the method enables the technology of binocular stereo matching to be employed in the three-dimensional shape measurement based on Fourier transform, avoids a complex process of phase unwrapping, does not need projection calibration, and can achieve a matching result with the sub-pixel level precision. The technology of binocular stereo matching is used for achieving rough matching, and a preliminary disparity map is obtained. Afterwards, the preliminary disparity map serves as a constraint condition and is used for the phase matching of a wrapped phase diagram obtained through Fourier transform. Finally, a three-dimensional point cloud diagram is generated. The method does not need any process of phase unwrapping in space or time, reduces the algorithm complexity, and avoids an error caused by the phase unwrapping. The method does not need projector calibration, avoids complex projector calibration, can enable a measurement process to be more simplified, also can avoid an error caused by the projector calibration, and is good in development prospect especially for the technology of quick three-dimensional measurement.

The invention relates to a method for solving a camera homography matrix and a projector homography matrix. The method for solving the camera homography matrix and the projector homography matrix is characterized in that a camera and a projector are both connected with a computer through cables, and the method comprises the following steps that in the computer, a camera calibration image is generated, in the computer, a projector calibration image is generated, and the camera calibration image and the projector calibration image are stored in the computer; the camera and the projector are fixedly placed on the front portion of a calibration plate, and it is guaranteed that the calibration plate is placed within the view field range of the camera and the projector; the calibration plate is taken through the camera, and a camera calibration plate image is obtained; the calibration plate is kept not be moved, the projector calibration image is all projected to the calibration plate through the projector, the camera is used for shooting the calibration plate, and a projector calibration plate image is obtained. According to the method for solving the camera homography matrix and the projector homography matrix, the camera and the projector can be quickly calibrated, and therefore the camera homography matrix and the projector homography matrix can be obtained.

The embodiment of the invention provides a speckle projector calibration parameter determination method for a monocular speckle structured light system. The method comprises the following steps: determining internal parameters of a camera; determining q mark points in a reference plane, and collecting images of the reference plane when the speckle projector is turned on and turned off when the camera is located at two different positions respectively; determining a plane equation of the reference plane in the images acquired by the camera at the two different positions based on three-dimensional coordinates of mark points in the images acquired by the camera at the two different positions in a camera coordinate system when the speckle projector is turned off; determining three-dimensionalcoordinates of speckle points and homonymy points in the camera coordinate system based on the plane equation and pixel coordinates of s speckle points and s homonymy points selected in the image whenthe speckle projector is started; and determining horizontal axis coordinates and vertical axis coordinates of the speckle projector based on the three-dimensional coordinates of the speckle spots and the homonymous points. According to the method provided by the embodiment of the invention, accurate calibration of the position parameters of the speckle projector is realized.

The invention relates to a structured light technology-based projector calibration method and belongs to the technical field of light measurement. The projector calibration method comprises the stepsof sensing brightness change of a structured light image obtained through a projector by using a light intensity sensing module through utilizing a structured light technology; establishing a relationship between the brightness change and an image of a to-be-calibrated projector; building and solving mathematic models of projector coordinates and world coordinates; obtaining an internal parametermatrix Min and an external parameter matrix Mex of the to-be-calibrated projector; and realizing the calibration of the projector. According to the method, a calibration object of any known three-dimensional structure can be used for performing the projector calibration, so that the additional cost required for the projector calibration is effectively reduced; and the light intensity change of a locating point is only collected during each circulation in the calibration process, and image coordinates corresponding to the locating point are only calculated, so that the algorithm difficulty andcomplexity of calculating a whole projection structured light region in an existing calibration method are lowered, the operation is simple, and the working efficiency of the projector calibration isimproved.

The invention is applicable to the technical field of optical measurement and provides a projector calibration method for multi-directional projection, which comprises: step S1, using a projector to sequentially project calibration patterns preset at N assigned positions preset around a target to a target plane, and collecting a target information map by using a camera at each assigned position; step S2, processing the target information map collected at each assigned position, calculating an accurate phase value of a target feature point, and further obtaining sub-pixel coordinates in a projector image coordinate system corresponding to the target feature point; step S3, calibrating the projector by using the sub-pixel coordinates in the projector image coordinate system and a three-dimensional world coordinate X of the known target feature point to obtain initial calibration parameters; and step S4, using a bundle adjustment method to optimize the initial calibration parameters and the three-dimensional world coordinate X to obtain final calibration parameters. The calibration method provided by the invention makes the final calibration results more accurate.

The invention discloses a calibration method of a surface structured light three-dimensional measurement system. The method comprises the following steps: calibrating internal parameters and distortion of a camera by using a glass checkerboard calibration plate covering a full field of view; respectively projecting left and right field-of-view projection images to a special calibration board whitearea of a semi-white semi-checkerboard pattern, and calibrating the internal reference and distortion of the projector; vertically moving the special calibration plate, and establishing a three-dimensional reconstruction coordinate system; calibrating camera external parameters and projector external parameters according to the three-dimensional reconstruction coordinate system. According to thecalibration method provided by the invention, a special calibration board with half white and half checkerboard is designed; the three-dimensional reconstruction coordinate system is constructed in cooperation with the vertical lifting platform to calibrate the projector, the camera and the surface structured light system, camera calibration, projector calibration and system external parameter calibration are separated in the overall calibration scheme and do not depend on a structured light algorithm, coupling interference of various errors in the calibration process is avoided, and thereforethe calibration precision is greatly improved.

A system for supporting a projector on a support structure relative to a projection surface includes a plurality of base members connectable with the support structure and having a position adjustable relative to the projection surface. The system also includes a base member calibration system for calibrating the base members to a predetermined position relative to the projection surface. The system also includes a plurality of foot members for supporting the projector. Each foot member has a position adjustable relative to the projector. The system further includes a projector calibration system for calibrating the projector to a predetermined position relative to the foot members. The projector calibrated to the predetermined position relative to the foot members is calibrated to the predetermined position relative to the projection surface when the foot members rest on the base members.

The invention discloses a projector calibration method and device for use in electronic equipment. The method comprises the steps of determining a row decoding value and a column decoding value of the Gray code based on each pattern in a received Gray code projection pattern group and each pattern in a line shift projection pattern group; determining each corner point in an all-white checkerboard calibration board pattern based on the received all-white checkerboard calibration board pattern; determining a projector coordinate system and a first position of each corner point in the projector coordinate system based on the row decoding value and the column decoding value; and according to the first position of each corner point in the projector coordinate system and a second position of each corner point in a world coordinate system, determining a corresponding relationship between the projector coordinate system and the world coordinate system, and calibrating the projector. In the projector calibration method provided by the invention, the accuracy of the calibration result is improved while the efficiency of the calibration process is ensured.

The invention discloses a camera and projector calibration system and method. The calibration system comprises a camera, a projector, a display screen for projection and a processor; the processor isconnected with the camera and the projector respectively, and sends trigger signals to the camera and the projector respectively; the camera comprises a camera lens, and the projector comprises a projection lens; the display screen is used for displaying a calibration pattern, and the color of the calibration pattern is variable; the projector is used for projecting a calibration image to the display screen; the camera is used for transmitting image data to the processor; the processor is used for calibrating the camera; the camera is also used for transmitting calibration data to the processor, and the processor is used for calibrating the camera and the projector. According to the camera and projector calibration system, the calibration relation between the camera and the projector of aprojection grating modeling system can be obtained, the modeling precision of a projection grating is high, and an established model is high in fidelity.

The invention provides a projector calibration method based on the Scheimpflug principle, and belongs to the technical field of 3D structured light measurement. According to the invention, the calculation precision of the phase is improved by using a bidirectional multi-frequency multi-step phase shift method with higher precision for the Scheimpflug projector, an imaging model of the Scheimpflug projector is constructed and combined with the existing Zhang's analytical algorithm to calculate the initial values of internal and external parameters, and the internal parameters, the external parameters and the distortion coefficient of the projector are optimized by using the LM algorithm; the LM algorithm is further utilized to optimize the Scheimpflug angle, so that the calibration precision of the projector is improved.

The invention discloses a projector calibration method, an intelligent terminal and a storage medium, the projector calibration method is applied to a projector calibration system, and the projector calibration method comprises the following steps: obtaining a calibration image corresponding to a calibration plate, and according to a preset coordinate parameter and the calibration image, generating a world coordinate system, a camera image plane coordinate system and a projector image plane coordinate system; calculating calibration parameters of the projector according to the calibration image, the world coordinate system, the projector image plane coordinate system and the camera image plane coordinate system; correcting the image plane coordinate system of the projector according to thecalibration parameters to generate a first coordinate system of the projector; and randomly selecting a plurality of collinear correction points in the calibration plate, and correcting the projectorfirst coordinate system according to the correction point world coordinates corresponding to the correction points and the correction point first coordinates corresponding to the correction points inthe projector first coordinate system to generate a projector second coordinate system. The calibration efficiency of the projector can be effectively improved.

The invention belongs to the abnormal projection field, and specifically relates to an intelligent abnormal projection non-contact interaction system and method. The intelligent abnormal projection non-contact interaction system and method aim at solving the non-contact interaction problem of abnormal plane projection. The intelligent abnormal projection non-contact interaction system includes a projection module, an image acquisition module, an abnormal projection calibrating module, a video production module and an interaction module, wherein the projection module is used for performing video projection, and generating an interaction area index plan when interaction projection is initialized; the image acquisition module is used for acquiring images of the interaction area in real time;the abnormal projection calibrating module includes camera calibration, projector calibration, and calibration of the camera and the projector at the same time; the video production module is used forproducing videos requiring projection, corresponding to the projector, and the corresponding interaction area chart on the abnormal plane; and the interaction module is used for detecting whether theacquired images of the interaction area have touch spots, selecting the corresponding projection images and sending the selected projection images to the projector to play projection according to thedetection result. The intelligent abnormal projection non-contact interaction system can realize the non-contact interaction function by means of the principle of machine vision, and can realize longdistance interaction projection play of large abnormal projection.

The invention discloses an analysis system and method for camera and projector calibration. The analysis system comprises a camera, a projector, a screen for projection and a processor. The processoris connected with the camera and the projector. The processor sends trigger signals to the camera and the projector. The camera shoots a screen only having the calibration pattern as a calibration image; the processor is used for acquiring camera calibration data; the projector is used for projecting a calibration picture; the camera is used for shooting a calibration picture of each brightness onthe screen as a picture image; the processor obtains the angular point position and the angular point phase of the calibration picture according to the picture image; the processor is used for acquiring the phase of each point of the calibration picture. According to the analysis system for camera and projector calibration, the calibration relation between the camera and the projector of the projection grating modeling system and the phase of the image projected by the projector can be obtained, so that the precision of projection grating modeling is higher, and the established model is morefidelity.