254 results about "Gray code" patented technology

The invention discloses an online monitoring method and system for the light transmittance of an optical lens, and relates to the technical field of precise optical detection. The objective of the invention is to solve the problem of large light transmittance calculation error caused by halo scattering noise interference, low optical path calibration precision of a complex curved lens, a measurement blind area of a large-aperture lens and environmental disturbance of a high-reflection / high-light-transmittance lens in the prior art. According to the scheme, a three-dimensional curved surface model is constructed based on Gray code structured light projection and ICP registration, a dynamic partition scanning instruction set is generated through an improved genetic algorithm, and multi-wavelength polarized light is driven to scan and collect multi-dimensional data; specular reflection and scattering noise are suppressed by combining an improved Stokes vector algorithm and an attention mechanism U-Net network, and the data precision of the complex curved surface is improved by adopting Bayesian optimization and Zernike polynomial weighted fusion; constructing a double-loop coupling optimization architecture to realize closed-loop adaptive optimization; according to the invention, the anti-interference capability, the complex lens adaptability and the full-aperture detection precision are obviously improved.

The invention belongs to the field of three-dimensional measurement, and discloses a three-dimensional reconstruction method based on structured light image enhancement, which comprises the following steps of: generating a stripe coding pattern: generating four sine stripe patterns with different phase shift amounts by using MATLAB programming, and projecting the sine stripe patterns to the surface of an object to be measured; calibrating a camera; calibrating a projector; the method comprises the following steps: capturing four phase shift stripe images projected on the surface of an object by using a camera, and preprocessing the stripe images collected by the camera through a GF-CL image enhancement algorithm; acquiring a wrapped phase: extracting wrapped phase distribution through a four-step phase calculation formula; generating a Gray code; carrying out binarization conversion; unwrapping the phase by using a complementary Gray code; and performing three-dimensional reconstruction. According to the invention, the contrast is improved by using an image enhancement algorithm, and noise is effectively removed. In addition, three-dimensional reconstruction is carried out by combining a four-step phase shift method and a complementary Gray code, so that the error of edge hopping in the traditional Gray code reconstruction is eliminated, and no hopping and interruption are ensured when a real phase is obtained.

The invention discloses a three-dimensional reconstruction method and system based on a line shift coding pattern, and the method comprises the steps: designing an original fringe pattern in a line shift manner to obtain a plurality of coding patterns, and carrying out the projection and collection of a to-be-measured object through the plurality of coding patterns and a preset Gray code pattern, respectively obtaining a plurality of fringe projection drawings and a plurality of Gray code projection drawings; synthesizing M phase shift fringe patterns according to the collected multiple fringe projection patterns; performing phase calculation on the M phase shift fringe diagrams to obtain a folded phase diagram; and combining the folded phase diagram with the plurality of Gray code projection drawings for phase unwrapping to obtain an unwrapped phase diagram, and reconstructing the to-be-measured object by using a three-dimensional reconstruction principle. According to the method, fringe synthesis is firstly carried out on the plurality of coding patterns, and then phase calculation is carried out on the M phase shift fringe patterns, so that three-dimensional reconstruction is carried out on the to-be-measured object by using the phase, relatively high reconstruction precision is achieved, the robustness is relatively high, and the method has a relatively good application effect in a high dynamic range scene.

The invention discloses a fringe projection three-dimensional shape measurement method based on frequency domain and time domain joint coding, and the method comprises the following steps: firstly, embedding a multi-frequency three-step phase shift fringe pattern in the vertical direction based on multi-scale region division, introducing four-step phase shift and complementary Gray code joint coding in the horizontal direction, generating a coding pattern set, and carrying out the projection; after an image is collected, frequency domain transformation and time domain decoding are carried out respectively, and a vertical dominant frequency position, a horizontal period number and a wrapped phase are obtained; then, combining a main frequency position in the vertical direction with a period number and a wrapped phase in the horizontal direction, and extracting a space coordinate of a direct illumination component based on frequency position invariance; and finally, establishing a pixel homonymy point mapping relation between the projector and the camera, and realizing high-precision three-dimensional reconstruction. Compared with a traditional frequency shift method, the method has the advantages that projection patterns are greatly reduced, reconstruction precision and anti-interference performance are improved, and the method is suitable for dynamic three-dimensional measurement under complex illumination conditions such as specular reflection, semitransparent shielding and subsurface scattering.

The invention discloses a three-coordinate structured light splicing method and system, and relates to the field of image processing, and the system comprises an acquisition module which is used for projecting a composite coding pattern through a structured light projection device, collecting workpiece surface deformation stripe images from preset multiple angles in cooperation with an industrial camera, and synchronously obtaining point cloud data under a structured light coordinate system, covering the whole surface features of the workpiece; according to the method, a composite coding pattern formed by combining a Gray code and a phase shift stripe is adopted, and self-adaptive exposure control and curvature-based path planning are combined, so that high-precision acquisition of complex curved surface details is realized, the phase calculation precision reaches a sub-pixel level, the scanning step length is dynamically adjusted according to the curvature of the curved surface, and the acquisition precision of a complex region is effectively improved.

The invention discloses a parameter calibration method and device for projection equipment, and the method and device have the following beneficial effects: (1) a checkerboard calibration plate does not need to be arranged in the calibration method, and the complexity and cost are reduced; (2) according to the calibration method, a series of Gray code images with coding information do not need to be projected, only one checkerboard image needs to be projected to the wall surface, and subsequent processing is carried out through photographing of the camera, so that the processing time is greatly shortened, and the efficiency is improved; (3) the projection light machine directly faces a wall surface and projects a checkerboard picture to the wall, and automatic focusing can be realized to adjust the definition of the projection picture; and (4) the focal length in the internal reference of the projection light machine and the Z-direction translation amount of the external reference between the projection light machine and the camera can be adaptively adjusted according to the motor step number after automatic focusing under different distances, finally parameter calibration of the projection equipment is realized, the processing process is simple, and the efficiency is high.

The invention relates to a polarization dislocation code fused phase shift coding method and system, and the method comprises the steps: obtaining calibration parameters of a camera and a projector, fusing a phase shift stripe pattern with a dislocation Gray code stripe pattern through the polarization characteristics of the projector, and obtaining a polarization dislocation fused phase shift stripe pattern; obtaining a deformed polarization dislocation fusion phase-shift stripe pattern after the projector projects the polarization dislocation fusion phase-shift stripe pattern to the surface of an object to be measured, extracting a phase-shift stripe pattern and a dislocation Gray code stripe pattern from the deformed polarization dislocation fusion phase-shift stripe pattern, and calculating a wrapped phase by using the extracted phase-shift stripe pattern, carrying out threshold processing on the staggered Gray code stripe pattern to obtain a binary Gray code pattern; and performing phase unwrapping on the wrapped phase through the binarization Gray code pattern, and performing three-dimensional reconstruction on the to-be-measured object through calibration parameters of the camera and the projector according to the unwrapped phase. According to the method disclosed by the invention, measurement errors caused by an underexposure or overexposure phenomenon are inhibited, and the measurement precision and the three-dimensional reconstruction efficiency are improved.

The invention provides a three-dimensional measurement method based on quaternary complementary Gray code auxiliary phase unwrapping. Comprising the following steps: generating, projecting and shooting a phase shift fringe pattern and a quaternary Gray code pattern; calculating a wrapped phase and average intensity; dividing the wrapped phase into two regions, generating binarization masks of the two regions, and obtaining a new wrapped phase by using a cut-off point translation technology; the average intensity and the scaling value of the average intensity are used as threshold values, gray code words are obtained, and two groups of levels are calculated; correcting the two groups of levels by using a strategy based on a connected region marking algorithm; performing phase unwrapping on the two groups of wrapped phases and levels; combining the two unwrapped phases to obtain a final unwrapped phase; and finally, subtracting the reference plane from the unwrapped phase, and converting phase information into height information through a phase height model. The three-dimensional measurement method based on the quaternary complementary Gray code auxiliary phase unwrapping is high in measurement efficiency, good in robustness and high in measurement result precision.

The invention relates to the technical field of data transmission processing, and provides an unmanned aerial vehicle communication-assisted ecological monitoring data transmission system and method, and the method comprises the steps: obtaining the ecological monitoring state parameters of an unmanned aerial vehicle; calculating an ecological monitoring obstruction coefficient and a dynamic disturbance coefficient of the unmanned aerial vehicle; calculating unmanned aerial vehicle cooperative interference loss weights, obtaining an ecological monitoring unmanned aerial vehicle transmission topological graph by using the unmanned aerial vehicle cooperative interference loss weights, recording unmanned aerial vehicle cooperative interference loss weight values with a preset time slot length as a cooperative interference loss weight sequence, calculating an adaptive interval adjustment length, and calculating a node screening threshold value; acquiring an ecological monitoring transmission bearing topological graph; and calculating a Gray code adaptive bit variation value of the ecological monitoring unmanned aerial vehicle, and performing transmission adjustment on transmission data of the ecological monitoring unmanned aerial vehicle by using the Gray code adaptive bit variation value of the ecological monitoring unmanned aerial vehicle. The reliability of the ecological monitoring unmanned aerial vehicle in the data transmission process is ensured.

The invention provides a mining surrounding rock mobile sensor and a separation amount measuring method. The surrounding rock moving sensor comprises a steel wire rope, and the light sensing measuring part comprises a light source, a light measuring module and a measuring strip. The light source is provided with a light output end capable of outputting light; the light measuring module and the light output end of the light source are located on the same straight line and used for receiving and decoding light signals. One end of the measuring strip is fixed with the steel wire rope, the measuring strip is arranged between the light source and the light ray measuring module, and scale codes are engraved on the measuring strip according to improved Gray codes; wherein when the steel wire rope is pulled, the measuring strip is driven to move, when the measuring strip moves, a light source can be emitted out through different Gray code carving holes in the measuring strip and is received by the light measuring module, and the light measuring module decodes received Gray code information and converts displacement of the measuring strip. According to the invention, the measurement accuracy of the separation amount can be effectively improved.

The invention discloses a semantic segmentation method based on phase contour constraint, and belongs to the technical field of computer vision. The method comprises the following steps of: acquiring a two-dimensional texture image and a deformed stripe image of a scene to be detected in the same view field by using a calibrated camera-projector system; resolving the deformed fringe image through a multi-step phase shift and Gray code technology to obtain absolute phase distribution, and calculating a gradient field; according to a preset sudden change condition, extracting a physical edge contour reflecting the depth change of the object from the gradient field; and mapping the physical edge contour into the two-dimensional texture image based on a pixel coordinate corresponding relation to accurately define a semantic object region, endowing a corresponding category label, and finally generating a semantic label mask image. According to the method, the uncertainty of the visual texture edge is corrected by utilizing the physical phase information, the problem of edge extraction in a complex illumination scene is effectively solved, automatic generation of semantic segmentation data is realized, and the training precision and robustness of a semantic segmentation model are improved.

A memory device includes a plurality of memory cells. Each memory cell stores a plurality of signal levels representing a plurality of values corresponding to a respective plurality of bits, bits in corresponding respective positions of significance across the plurality of memory cells constituting respective memory pages of the memory device. The memory device also includes decoding circuitry to decode each bit value of one of the respective memory pages using bit values read from at least one other one of the respective memory pages, adjacent to the one of the respective memory pages. The plurality of signal levels may represent the plurality of values according to a Gray code. The decoding circuitry may be configured to compare each signal level to a set of voltage thresholds, and to decode a subset of the plurality of signal levels using fewer than all voltage thresholds in the set of voltage thresholds.

The invention discloses a transparent glass surface shape measuring device and a transparent glass surface shape measuring method based on stereoscopic deflection, a plane mirror is introduced to complete calibration work, global system parameters are optimized according to re-projection results of the plane mirror, system calibration flexibility is improved, and calibration precision is improved. Glass to be detected can be placed at any position in a to-be-detected area on a carrying platform without fixing, a Gray code auxiliary line shift fringe technology is adopted as a coding and unfolding scheme, the coding scheme is completely based on a binary coding method, a modulation graph has the characteristic of spatial separation, coding information is easier to extract, and the coding efficiency is improved. The reflection information of the upper surface of the glass is extracted through a self-adaptive method based on a clustering algorithm, threshold parameters do not need to be set manually, a pure vision scheme is adopted, the method has the advantages of being low in cost, large in dynamic measurement range and the like, and the measurement precision meets the actual industrial measurement requirement.

The invention discloses a phase deflection measurement method and device based on four-step phase shift, and belongs to the technical field of computer vision and precision measurement, and the method comprises the steps: S1, classifying patterns needing to be projected according to types, and fusing the patterns into a color image; s2, sequentially projecting color images, and simultaneously collecting a pattern modulated and reflected by an object to be measured to obtain a reflection pattern; s3, carrying out channel separation processing on the reflection pattern, recovering the reflection pattern into an original grey-scale map, and respectively obtaining all phase patterns and Gray code patterns in the horizontal direction and the vertical direction; s4, performing phase calculation and Gray code auxiliary positioning according to the phase pattern and the Gray code pattern to obtain an absolute phase; and S5, mapping the absolute phase into a depth value, and recovering the three-dimensional shape of the surface of the object to be measured in combination with calibration parameters of a camera-projection system. The time of each measurement period is shortened, the system delay in the projection and acquisition process is reduced, and the real-time response capability of the whole set of detection system is improved.

The invention discloses an underwater high-speed three-dimensional measurement method based on stripe structured light, and relates to the technical field of underwater optical three-dimensional imaging, in an underwater operation scene of an FPP system, projecting a three-step phase shift sine stripe and a Gray code pattern to an object to be measured, and respectively calculating a wrapped phase 1, a wrapped phase 2 and an auxiliary order phase; analyzing the light intensity information received by the camera, and carrying out water body influence analysis in combination with an underwater light transmission model; the initial wrapped phase divides the order phase into a stable region and a non-stable region, the stable region is combined with the wrapped phase 1 to calculate a preliminary absolute phase, and the non-stable region is combined with the wrapped phase 2 to calculate an absolute phase through an island processing method. According to the method, a phase bisection complementary decoding strategy is adopted, a jump error region in an order phase is effectively identified and corrected by constructing complementary wrapped phase information, a wrong order phase is corrected by using a noise correction algorithm, and the measurement stability in a dynamic scene is remarkably improved.

The invention discloses a digital grating projection three-dimensional reconstruction method in a mutual reflection environment, and the method comprises the steps: determining a first frequency and a second frequency of a phase shift image and a Gray code image marking a stripe period, generating a first group of multi-step phase shift images and a second group of multi-step phase shift images, and projecting the images to the surface of an object; capturing a fringe image reflected and modulated by the surface of the object, acquiring a first wrapping phase based on the first group of multi-step phase shift images, acquiring a second wrapping phase based on the second group of multi-step phase shift images, and judging whether two wrapping phases of pixels at the same position accord with the wrapping phase relationship determined by the two frequencies; if not, determining that the pixel at the position has phase interference and filtering the phase interference; and obtaining an absolute phase based on the wrapping phase of the residual position pixels and the fringe periodicity determined by the Gray code image, and calculating the height of the object by combining the calibrated phase and height conversion model to generate an object point cloud. According to the invention, wrong phases caused by mutual reflection can be effectively removed.

The invention discloses an optical Gray code encoder temperature compensation method and system based on an NTC resistance network, and the method comprises the steps: calibrating a PD signal drift law in a working temperature range, designing an NTC voltage division circuit matched with the law, and integrating the NTC voltage division circuit to a comparator, thereby achieving the real-time offset of the PD signal temperature drift. According to the scheme, the defects that in the prior art, complexity is high and cost is high are overcome, compensation precision within + / -0.5% is achieved only through basic electronic elements, the response speed reaches the microsecond level, cost is reduced by 60% or above, the method is suitable for wide-temperature-range scenes ranging from-40 DEG C to 85 DEG C, and a low-cost and high-precision temperature compensation solution is provided for precise measurement of high-end equipment.

The invention relates to a structured light-assisted binocular stereo matching fusion method, system and device and a medium. The method comprises the following steps: projecting a plurality of groups of high-frequency sine stripes to the surface of a target object, and superimposing and projecting a Gray code pattern; shooting the surface of the target object to obtain left and right images; and extracting a wrapped phase from the left and right images, and calculating to obtain an absolute phase according to the wrapped phase and the decoded information of the Gray code pattern. And calculating the matching cost of each pixel in the left image and the right image under different parallax, and carrying out cost aggregation processing in a parallax space by taking an absolute phase as a constraint to obtain a parallax map. And optimizing the disparity map to obtain the optimal disparity. And generating a three-dimensional point cloud according to the optimal parallax and the calibration parameters. According to the method, texture information can be enhanced, and the reconstruction integrity and geometric accuracy of weak-texture and high-reflection non-abandoned products are remarkably improved.

The invention discloses a three-dimensional vision reconstruction method based on differential Gray coding structured light, which comprises the following steps of: projecting N phase shift fringe pictures by using a projector, and acquiring a fringe pattern projected to a measured object from a camera to solve a folding phase; the projector projects log2T + 1 Gray code pictures and the same number of differential Gray code pictures, every two Gray code pictures form a group, and T is the fringe period number of the phase shift picture; calculating a mean value of the Gray code graph and the differential Gray code graph in each group, carrying out binarization segmentation on the Gray code, and solving a stripe order; and unfolding a folded phase by using a stripe order, and realizing three-dimensional reconstruction of an object by combining calibration parameters of a camera projector. Aiming at strong scattering environments such as turbid underwater, the problem of picture segmentation in different environments is solved, and by additionally adding a Gray code picture, order edge part code words which are easy to cause errors are prevented from being used when a folded phase is unfolded, so that the method has higher adaptive capacity and ensures the precision of final three-dimensional reconstruction.

According to the combined phase estimation and defocusing fuzzy data set generation method provided by the invention, matching is carried out after a full-bright image is projected, so that the shadow defect can be avoided, and the depth estimation of the shadow part of the projected image is correct; structured light projection fringes are improved, Gray codes and phase shift codes are combined, the moire phenomenon is avoided, and accurate edge parallax is obtained. The invention also provides a DPD-based joint phase estimation and defocusing fuzzy network forming method, and the method comprises the steps: setting an independent parallax estimation module, and obtaining an accurate parallax result; according to the parallax image, an image alignment module is added, the deblurring performance is improved, and parallax estimation is more accurate. The invention further provides a QPD-based combined phase estimation and defocusing fuzzy network forming method, parallax fusion and feature fusion are carried out by fully utilizing parallax information and image feature information according to the imaging principle of a QPD image sensor, and a clearer deblurring effect and a more accurate depth estimation effect are obtained.

The invention discloses a multifunctional data acquisition and transmission system based on PXIe, and belongs to the technical field of high-speed data acquisition and real-time transmission. The system comprises a data acquisition module, an analog output module, a PXIe data transmission module and a high-speed board-to-board connector, the data acquisition module acquires analog signals through an A / D conversion unit, and after cross-clock domain synchronization and rate matching are achieved through an asynchronous double-clock FIFO cache unit, the analog signals are packaged by an FPGA control unit and transmitted to an upper computer at a high speed through a DMA engine of a PXIe interface; the analog output module receives instructions of an upper computer through the FPGA, digital signals are buffered through asynchronous FIFO, analog signals are output through the D / A conversion unit, and a two-way data link is formed. The innovative design of the method comprises the following steps of: eliminating a metastable state risk by adopting asynchronous FIFO (First In First Out) synchronized by a Gray code pointer, triggering a pause / recovery signal through a threshold value in combination with an FPGA (Field Programmable Gate Array) dynamic flow control strategy to prevent data overflow or cut-off, and optimizing a PXIe DMA engine to realize high-speed transmission so as to reduce a CPU (Central Processing Unit) load. The system can be used in the fields of industrial automatic testing, high-precision instruments and real-time signal processing.

A method of reducing jitter in transmission of a timestamp across a clock domain boundary includes storing N timestamps, generated in N successive clock cycles of an origin clock domain, in N parallel buffers in the origin clock domain under control of a modulo-N counter, transmitting outputs of the N parallel buffers across the clock domain boundary into a destination clock domain along with the modulo-N counter, processing the modulo-N counter in the destination clock domain to derive a selection signal that selects a stable timestamp from among the outputs of the N parallel buffers, and outputting the selected stable timestamp. The modulo-N counter may be Gray-coded modulo-N counter to reduce jitter in the modulo-N counter across the clock domain boundary.

A face identification system, and a non-transitory computer readable medium with instructions, that when executed, perform a method for identifying a face image are described. The face identification system comprises a camera for facial image capture, encryption circuitry for image encryption, feature extraction circuitry for processing encrypted images, a face recognition system for identification, and an identification notifying system for result transmission. The encryption circuitry includes a pixel-bit converter, transforming pixel intensities into binary digits, and a 2D cellular automata function, working with a 3×3 matrix of binary-state cells transitioning by update rules. A gray code generator maps binary numbers to unique gray-scale values. The system integrates advanced encryption techniques with efficient feature extraction and recognition algorithms, addressing challenges in biometric authentication. This approach enhances security, accuracy, and computational efficiency compared to conventional systems, making it suitable for various applications requiring secure and efficient facial recognition.

An arithmetic logic unit (ALU) includes a front end latch stage coupled to a Gray code (GC) generator to latch GC outputs, a signal latch stage coupled to latch outputs of the front end latch stage, a GC to binary stage coupled to generate a binary representation of the GC outputs, an adder stage including first inputs coupled to receive outputs of the GC to binary stage, a pre-latch stage coupled to latch outputs of the adder stage, and a feedback latch stage coupled to latch outputs of the pre-latch stage in response to a feedback latch enable signal. The feedback latch enable signal is one of a correlated multiple sampling (CMS) feedback enable signal and a non-CMS feedback enable signal. The ALU is configured to perform CMS calculations in response to the CMS feedback enable signal and perform non-CMS calculations in response to the non-CMS feedback enable signal.

The invention relates to the field of meteorological information processing, and discloses a ground wind direction observation data anomaly detection method. The main process comprises the following steps: estimating wind direction change model parameters according to acquired wind direction observation data in a specified window, establishing a wind direction change model, and recording wind direction statistical information by adopting a sparse angle wind direction drop point precursor table; modeling wind direction data into a random walk process in a degree range, and finding a sparse or air-wind direction interval to find a potential abnormal condition; the subsequent distribution of wind direction points in a non-sparse interval or a non-empty interval is investigated, and whether the wind direction sequence is abnormal or not is judged by utilizing a method for judging whether the wind direction points belong to an atypical wind direction sequence mode with minimum probability or not. The detection method provided by the invention does not depend on a specific Gray code coding principle, has wind direction abnormal sequence detection generality, can detect a complex wind direction abnormal mode, avoids misjudgment caused by long-time stable and little change of a real wind direction, and improves the robustness of the detection method.

The invention discloses a clock processing method and device, electronic equipment, a storage medium and a program product, and relates to the technical field of communication, and the method comprises the steps: building a cross-domain clock based on a main clock in a digital circuit; setting a first delay constraint for the cross-domain clock based on a preset delay threshold; the Gray code path is determined in the time sequence path corresponding to the cross-domain clock, and the first delay constraint is adjusted based on the clock frequency of the cross-domain clock to obtain the second delay constraint, so that the problems that the requirements of different types of time sequence paths on path constraints are often different, and if the constraints are not distinguished when the time sequence paths are designed, the time sequence paths cannot be designed are solved. The technical problem that the power consumption of the digital circuit is increased due to the fact that a design tool may add more buffers on a path or enhance the driving capability of the buffers is solved, and the technical effect of reducing the power consumption of the digital circuit to a certain extent on the premise of ensuring the time sequence requirement of the cross-clock domain is achieved.

The invention discloses a metal induction type angle measuring module and measuring device.The metal induction type angle measuring module comprises a mounting disc, a coding disc and a plurality of metal inductors, the coding disc is rotatably arranged around the central axis of the coding disc, the coding disc is provided with a code channel, the code channel is provided with a plurality of sectors in the circumferential direction of the code channel, and the sectors are arranged in the mounting disc; each sector is coded according to a Gray code mode to form a metal sector and a non-metal sector; the plurality of metal sensors are arranged at the mounting disc in a one-to-one correspondence to the code channels, each metal sensor forms an initial electric field quantity and / or an initial magnetic field quantity, and the initial electric field quantity and / or the initial magnetic field quantity are / is changed when the metal sector movably passes through. According to the invention, the metal inductor realizes non-contact detection, and has the advantages of high response speed, high reliability, low possibility of being influenced by external environmental factors, wide application range, simplicity and convenience in installation and high anti-interference capability, so that the use reliability of the whole machine is higher.

The invention provides a projector high-precision calibration method capable of overcoming nonlinear errors, which adopts a phase encoding technology and obtains an absolute phase value by projecting a Gray code and a sine stripe pattern. Hilbert transform is used for compensating phase errors, and errors caused by nonlinear factors of a projector and a camera are reduced. The feature points of the calibration plate are converted from a camera pixel coordinate system to a projector coordinate system through a local homography matrix, and the influence of non-linear errors on calibration precision is further reduced. And finally, calibrating the projector by using a Zhang Zhengyou calibration method to obtain internal and external parameters of the projector. The method can effectively improve the calibration precision and reduce the calibration difficulty.

The invention relates to a fringe projection high-reflection surface phase unwrapping method based on frequency reuse. The fringe projection high-reflection surface phase unwrapping method comprises the steps of collecting a multi-frequency fringe image and dividing the multi-frequency fringe image into an overexposure area and a non-overexposure area, solving a wrapped phase in the non-overexposure area by adopting a generalized phase shift method, obtaining an initial unwrapping phase based on a multi-frequency heterodyne algorithm, and performing block filtering and interpolation processing to obtain a fringe projection high-reflection surface phase unwrapping phase. A continuous unwrapped phase containing a high-reflection area is obtained, a complementary Gray code consistent with a wrapped phase period is constructed in combination with a multi-threshold constraint and is used for correcting the stripe level of an overexposure area, brightness attenuation design is further carried out on low and medium frequency stripes, frequency reuse is achieved, and the high-reflection area is obtained. Obtaining an unwrapped phase of an overexposure point in a non-high-frequency stripe and mapping the unwrapped phase to a high frequency; the method comprises the following steps of: extracting and fusing a wrapped phase by adopting one-dimensional Fourier and Hilbert transform for areas with overexposure of each frequency, and selecting and inhibiting spectrum leakage through a complete period, so that effective correction of the wrapped phase and stripe level of an overexposure point is realized, and a reliable unwrapped phase is obtained.

The invention relates to the technical field of fringe projection three-dimensional reconstruction, in particular to a point cloud enhancement method and system based on polarization structure perception and trend guided recovery. The method comprises the following steps: acquiring a multi-angle polarization image, and generating an object area mask based on a polarization angle consistency mask, a polarization angle gradient mask and a linear polarization degree mask; obtaining an original phase diagram through four-step phase shift and complementary Gray codes, obtaining a missing region in an object according to hole distribution of the original phase diagram, and adding morphological structure indexes and local variance features to recognize a real self-shadow region; aiming at the identified real self-shadow area, establishing a structure guiding recovery model combining a first-order structure gradient guiding item and a second-order structure gradient guiding item to obtain a complete object point cloud; and separating a background and an invalid shadow in the object point cloud through the object area mask to obtain a point cloud which only retains the object area.