105 results about "Speckle imaging" patented technology

The invention relates to a three-dimensional scanning system, which is used for obtaining three-dimensional stripe point cloud data of a detected object. The system comprises: a light source, which successively and alternately projects multiple speckle patterns and stripe patterns on the detected object; a left camera and a right camera, which synchronously collect left and right speckle images and left and right stripe images of the detected object; a speckle data and sign point data reconstruction module, which obtains speckle three-dimensional data and sign point three-dimensional data on the basis of the speckle images; a stripe matching module, which conducts back projection onto the left and right stripe images according to the speckle three-dimensional data and the sign point three-dimensional data, and guides matching for stripes of the left and right stripe images; and a three-dimensional reconstruction module, which reconstructs the corresponding matched stripes of the left and right stripe images into three-dimensional stripe point cloud data. The invention also provides a scanning method of the three-dimensional scanning system.

One embodiment relates to an optical displacement sensor for sensing transverse displacement of a data input device relative to a surface by determining displacement of optical features in a succession of frames. The sensor includes at least a coherent light source, illumination optics to illuminate a portion of the surface, imaging optics, and a first array of photosensitive elements having a periodic distance. The illuminator and the detector are configured to produce on the first array of photosensitive elements an intensity pattern of light reflected from the illuminated portion of the surface. The intensity pattern comprises a plurality of speckles having an average speckle diameter which is between one half and two times the periodic distance of the array.

The invention relates to a three-dimensional deformation measuring system and a three-dimensional deformation measuring method combining speckle correlation and speckle interference. The system comprises a laser, wherein laser light emitted by the laser passes through a semi-permeable and semi-reflective mirror after being expanded for illuminating a tested object and a reference object surface respectively; the tested object surface and the reference object surface are imaged simultaneously on the target surface of a CCD (Charge Coupled Device) camera through an imaging lens by means of the semi-permeable and semi-reflective mirror; the semi-permeable and semi-reflective mirror is arranged obliquely at an angle of 45 degrees relative to incident rays; and when a reference path exists, object surface speckles and reference surface speckles are interfered with mutually on the target surface of the CCD camera to form an interference speckle image for measuring an off-plane displacement component. A reference substance light path is removed, a speckle image on the object surface is acquired, and two components of in-plane displacement are calculated by using two speckle images acquired before and after deformation. A typical digital speckle light path which is sensitive to the off-plane displacement is utilized, so that the in-plane displacement and speckle interference off-plane displacement of a speckle relevance measuring object are realized, and three-dimensional displacement measurement is realized; and and the system and the method have the advantages of simple light path, and easiness and rapidness for operating and processing data.

The invention discloses a welding deformation real-time detection system. The welding deformation real-time detection system is characterized by comprising a CCD camera (4), an environment light source (5), a detection module and a control module, the CCD camera (4) is used for generating a speckle field and forming speckle images on the surface of an irradiated welding workpiece, and then collecting the speckle images on all the stages of welding of the surface of the welding workpiece, the environment light source (5) is used for providing lighting of the surrounding of the welding workpiece when the speckle images are collected, the detection module is used for processing the collected speckle images, and recognizing three-dimensional coordinate changes of a deformation point, on the surface of the welding workpiece, on the speckle images according to the speckle images of all the stages so as to obtain a three-dimensional displacement field and a strain field of the surface of the welding workpiece, and the control module is used for providing electric power support for the CCD camera and having control over the image collection process. According to a detection method of the welding deformation real-time detection system, the cost is reduced, efficiency and accuracy are improved, and the great actual use value, and the economic and social benefits are achieved.

A portable optical sensor for measuring surface strain in an object, such as pre-stressed concrete articles, is provided. The sensor is a modular device comprising at least first and second modules, each of which includes a laser and image sensor. When placed adjacent to the object, the laser of each module illuminates respective, spaced-apart areas of the object's surface and each module's image sensor captures at least a portion of the light reflected from the illuminated area and generates a speckle image of the area. Speckle images of the areas taken at various times and / or under various object stress conditions are compared to arrive at a surface strain measurement for the object.

The invention provides a speckle image quality recognition method and system based on image feature description, and the method comprises the steps: collecting target speckle images; carrying out the preprocessing of the target speckles image according to the source of each target speckle image; extracting the features of each target speckle image, carrying out the histogram feature description and PCA (principal component analysis) of each target speckle image according to the extracted image features, and obtaining a standard speckle image and a standard parameter vector; and carrying out the comparison and recognition of the target speckle images and the standard speckle image or the standard parameter vector. The system comprises a collection module, a preprocessing module, a standard obtaining module, and a recognition module. The method and system are high in recognition precision, are small in calculation burden, are high in calculation speed, accurately and effectively achieve the quality recognition of the speckle images, enables the detection result of the speckle interference measurement to be precise and reliable, and provides precise technical support for the detection application research of deformation or displacement information of an object.

The invention relates to a three-direction displacement measurement method based on a laser speckle imaging technology. The three-direction displacement measurement method based on the laser speckle imaging technology can achieve synchronous three-direction displacement measurement. According to the technical scheme, the method includes the following steps that firstly, two laser transmitter sets are installed on a reference point, and a laser speckle imaging system is installed on a position I; secondly, light beams are transmitted to an imaging target surface by the laser transmitters and are focused to form a speckle image by an imaging lens, the speckle image is received by an imaging photoelectric device, and the coordinate values of the center points of two speckles relative to the imaging system are found out by a signal processing unit through an image processing algorithm and serve as original values; thirdly, the laser speckle imaging system is moved to a position II, light beams are transmitted to the imaging target surface by the laser transmitters, and the coordinate values of the center points of two speckles relative to the imaging system are found out and serve as test values; fourthly, the test values are compared with the original values, and the horizontal displacement and the vertical displacement are worked out; fifthly, the three-direction displacement of the position II where test points are located relative to the position I is worked out.

The present invention discloses a depth acquisition method for a complex scene, and the depth acquisition method can improve the depth image acquisition precision and further improve the robustness. The depth acquisition method for the complex scene comprises the following steps of: (a) designing and coding multi-password structured light patterns according to a signal-to-noise ratio of a speckle image and a relationship between the depth precision and the speckle density, projecting the multi-password structured light patterns onto a to-be-measured object through light-emitting equipment respectively, and generating a projected mixed multi-password structured light pattern; (b) generating a multi-density mixed reference image, and shooting and recording a modulated image of the projected coded structured light pattern of the to-be-measured object by using a camera having a certain angle with the light-emitting equipment; (c) rapidly matching the projected structured light pattern with the shot and modulated image, and further obtaining the offset of a corresponding matching point before and after projection; and (d) calculating the depth value of the matching point according to the offset and acquiring the depth data of the to-be-measured object.

A non-invasive method for measuring blood flow in principal vessels of a heart of a subject is provided. The method includes illuminating a region of interest in the heart with a coherent light source, wherein the coherent light source has a wavelength of from about 600 nm to about 1100 nm; sequentially acquiring at least two speckle images of the region of interest in the heart during a fixed time period, wherein sequentially acquiring the at least two speckle images comprises acquiring the at least two speckle images in synchronization with motion of the heart of the subject; and electronically processing the at least two acquired speckle images based on the temporal variation of the pixel intensities in the at least two acquired speckle images to generate a laser speckle contrast imaging (LSCI) image and determine spatial distribution of blood flow rate in the principal vessels and quantify perfusion distribution in tissue in the region of interest in the heart from the LSCI image.

The invention relates to a measurement system and a method for detecting ocular fundus blood flow velocity with high resolution. The measurement system is characterized in that a bacon light source is focused on the fundus by a human eye through a plurality of optical components to form a bacon spot; the spot is transformed into parallel light through the eye after backward reflection, and reaches a wavefront sensor through a wavefront phase corrector and a series of optical components to realize the process of self adaptive aberration correction; the imaging light source is focused on the front focus of the eye through the optical components, and is collimated by the eye into the parallel light to illuminate the retinal vascular microcirculation system; a laser speckle interferometry is formed on the surfaces of the fundus blood vessels illuminated; the interference field enters into wavefront phase corrector through the optical components and is reflected and finally focused on a photodetector through the series of optical components; a light speckle imaging process is realized. The measurement method has the advantage of enabling the whole system to overcome negative influences from the aberration of human eyes on capturing laser speckle interference field images, thus facilitating to obtain fundus velocity graph of high precision and resolution.

The invention discloses a frequency domain laser speckle imaging based blood flow velocity measuring method. The frequency domain laser speckle imaging based blood flow velocity measuring method comprises the following steps of illuminating laser beams on a measured object, imaging the measured object through an imaging system, collecting an original speckle image of the measured object through an image sensor, transferring dynamic speckle intensity with single pixel points being in a time domain of the collected original speckle image into a frequency domain, calculating the power spectral density, performing polynomial fitting on the power spectral density to obtain a smooth curve, transferring the smooth curve into the time domain through Fourier transform, calculating an autocovariance function of the pixel points and performing normalization, establishing a blood velocity measuring model, obtaining a relationship between the covariance function and the blood velocity and finally performing fitting to obtain a blood velocity value. The frequency domain laser speckle imaging based blood flow velocity measuring method has the advantages of not only eliminating static noise, improving the blood velocity measuring accuracy, avoiding influences from imaging environmental factors such as intensity and illumination angles and improving the measuring stability.

The invention relates to an electronic speckle-interference digital-compensating method with simple operation and higher precision and a system thereof. The method comprises the following steps of: 1) fixing a measured object onto a loading device, acquiring four four-step phase-shifting speckle images before loading, and moving a plane mirror through a phase shifter to change the optical-path difference of reference light and object light to realize phase shifting; 2) after loading the measured object, reacquiring four four-step phase-shifting speckle images by a method which is similar to the step 1); 3) calculating the corresponding in-plane two-dimensional displacement of a first phase-shifting speckle image before and after deformation by a two-dimensional digital-speckle related method; 4) carrying out reverse displacement for mismatched speckle-field images before and after deformation by a digital operation method to realize the realignment of speckle fields before and after deformation; and 5) calculating the phase difference corresponding to the deformation before and after loading by a direct phase-difference solving method.

The invention discloses a depth image acquisition method, a depth image acquisition module and electronic equipment. The depth image acquisition module comprises a first camera, a second camera, a third camera, a light projector and a processor. The first camera is used for shooting a preview image, and the processor obtains the environment brightness of the scene according to the preview image. And when the ambient brightness is greater than the preset brightness, the first camera shoots a visible light image of the scene, the second camera shoots a grayscale image of the scene, and the processor calculates a depth image of the scene according to the visible light image and the grayscale image. When the ambient brightness is smaller than the preset brightness, the light projector projectsinfrared light into the scene to form a speckle pattern, the second camera shoots a first speckle image of the scene, the third camera shoots a second speckle image of the scene, and the processor calculates a depth image of the scene according to the first speckle image and the second speckle image.

Disclosed are an image acquisition method, an image acquisition device, a structured light assembly, and an electronic device. The image acquisition method comprises the following steps of: controlling the structured light camera to receive the speckle image by diffracting the structured light diffracted by the display area of the display screen and directly incident after being reflected by the target object; Filtering a second measurement speckle in the speckle image to obtain a first measurement speckle; And acquiring a depth image based on the first measured speckle and the reference speckle in the reference image. The structured light projector and the structured light camera can be arranged under the display screen, and the influence of the display screen on the structured light canbe eliminated by filtering the second measuring spot in the speckle image, so that the depth image acquired by the electronic device is high in accuracy under the condition that the screen occupancy of the electronic device is high.

The invention discloses a digital image correlation method based on local grid encryption. The method comprises the following steps: setting a gray threshold value, performing crack detection and recognition operation on speckle images one by one to obtain binarized analysis images corresponding to the speckle images, and recording coordinate information of crack boundaries in the binarized analysis images to determine a grid area needing to be encrypted; the method comprises the following steps of: setting a subset spacing, firstly generating uniform grids with equal pixel spacing in a binarization analysis image, and then executing grid encryption operation around a crack boundary expanded by the binarization analysis image according to crack boundary coordinate information recorded by the binarization analysis image corresponding to a reference image; and executing image processing analysis to obtain full-field displacement and strain information. According to the method, the function of densifying grids around the crack boundary in the image analysis process can be achieved for the problem of discontinuous deformation generated by quasi-brittle materials such as concrete and rock, and the precision of displacement and strain measurement results near the crack can be improved.

The invention provides a digital double-micro speckle measuring method for strain. The invention relates to the measuring method for the stress and the strain of a structure, in particular to the measuring method for the stain with application of the photoelectron technology. The CCD with a micro-lens is arranged on a fixed platform while two CCDs serve as a group in the invention; when in measuring, a speckle field is manufactured on the surface of the measured object and the speckle images of the measured object in the scale distance between two points before and after being loaded are collected by the double-CCD synchronously and then are operated by the related processing software after being transmitted into a PC machine, at last, the mechanics parameter of the measured object can be obtained. The invention has short detection period, low consumption of resources, low detection cost, good economic benefit, easy interpretation and convenient and wide application. Meanwhile, the method can be used for detecting and evaluating the safety performance of other large buildings, such as houses, large dams, etc.

The invention provides a method for monitoring the seismic deformation of a building curtain wall based on digital speckle marks, and the method comprises the following basic steps: 1) fixing a test piece frame on an earthquake simulation vibration platform, assembling a to-be-detected curtain wall on the frame, and manually marking speckle patterns with random characteristics on the surface of the curtain wall; 2) erecting two industrial digital cameras to image speckle patterns on the surface of the test piece; 3) fitting artificial seismic waves according to the characteristics of a plannedconstruction site, carrying out graded loading for multiple times, and collecting speckle images at the same time; 4) performing three-dimensional digital image correlation matching calculation of the acquired digital image sequence in a computer to obtain full-field displacement and deformation information of the surface of the building curtain wall under the action of a seismic load. Through the digital speckle image marking and optical measurement method, the quantitative data of the full-field deformation of the curtain wall under the earthquake load effect is obtained, the measurement result is more accurate, the measurement steps are simpler, and the application range is wider.

The invention discloses a stereoscopic vision measurement manual mark point based on speckle image matching. The manual mark point is a three-layer ring-shaped structure which is composed of a black ring in the outer, a white ring in the middle, and speckle patterns in the inner. A positioning method includes the following steps: firstly, in the process of testing an image, based on the information of the white ring and the speckle pattern blocks, detecting manual mark points; then conducting subpixel-level precision matching in a stereoscopic image by using a speckle image matching method; eventually based on the calibration result of a stereoscopic vision measurement system, conducting 3D construction to obtain the 3D coordinates of the manual mark points. According to the invention, themanual mark point pattern form and positioning method can effectively eliminate interference imposed by dazzling light on the surface of a to-be-tested target, and increase the robustness of a visionmeasurement system.

The invention discloses a rotating blade underwater dynamic deformation binocular measurement system of a composite material propeller model, and relates to the technical field of propeller testing. The system comprises two cameras, white light stroboscopic light source equipment, a synchronizer, a software system, optical auxiliary equipment, a target and a dynamometer; the two cameras are arranged beside an observation window in the side of a water drum test section; the white light stroboscopic light source equipment is arranged at an observation window in the upper portion of the water drum test section; the synchronizer is connected with the cameras, the software system and the dynamometer and controls synchronous work of the cameras, the software system and the dynamometer; the target is arranged at a to-be-tested area, and the two cameras shoot at least eight pairs of speckle images, at different positions and in different directions, of the target; the software system is in charge of collecting the speckle images and conducting subsequent correlation analysis; the optical auxiliary equipment is arranged on the observation window in the side of the water drum test section. According to the system, through non-contact optical measurement, the speckle images of blades are obtained, real-time deformation features of composite material blades are obtained correlation analysis, and thus guidance in design and optimization of the composite material propeller is achieved.

The invention discloses multi-modality imaging equipment combining opto-acoustic imaging and laser speckle imaging. The multi-modality imaging equipment combining opto-acoustic imaging and laser speckle imaging comprises a 532nm pulse laser source, a 632.8nm He-Ne laser source, an opto-acoustic modulating light path, a laser speckle modulating light path, a reflector group, an opto-acoustic signalacquiring system, a laser speckle blood flow acquiring system and an upper computer. The multi-modality imaging equipment combining opto-acoustic imaging and laser speckle imaging disclosed by the invention can detect haemodynamics parameters including cellular structures in blood vessels, blood flow and the like continuously and simultaneously in a real-time same-view-field manner, and effectively and accurately transmit the acquired multi-modality parameters to the upper computer for processing; and besides, the composition of the multi-modality imaging equipment can be simplified, and high-distinguishability opto-acoustic imaging and laser speckle blood flow imaging are effectively combined, so that the measuring steps and the measuring time of different parameters are greatly reduced,and strong support is provided for clinical diagnosis and treatment of vascular diseases in future.

The invention provides an MEMS galvanometer for inhibiting laser speckles in a laser display system and a manufacturing method of the MEMS galvanometer. An SOI (Silicon-On-Insulator) is used as a processing object of the MEMS galvanometer; the MEMS galvanometer is manufactured by micro-processing technologies such as photoetching, etching and coating and mainly comprises a reflective mirror, a resonance suspension girder, driving comb teeth, detecting comb teeth and the like. Tiny waving features which are distributed randomly are designed on the surface of the reflective mirror, and a function of inhibiting the speckles is fulfilled by interfering laser phase while laser reflection is realized. The driving comb teeth, the detecting comb teeth and the resonance beam structure which are matched with the reflective mirror are designed on the reflective mirror, by electrostatic drive of the comb teeth, in-plane vibration of the reflective mirror can be realized, the contrast ratio of the speckles is reduced due to time average by stacking of speckle images in human visual retention time, and the speckle inhibiting effect of the device is improved. The laser speckle inhibiting device in an MEMS galvanometer mode has the characteristics of high reliability, low energy consumption, obvious speckle inhibiting effect, simplicity in processing, easiness in large-scale production and the like.

The invention provides a speckle manufacturing method based on a transfer print technology. The method includes the steps that the size, the number, the deformation and other parameters of speckles are input through computer software, so that two or more pairs of speckle images are generated; digital speckle correlation operation is performed on all the speckle images through the software, and the speckle image highest in speckle matching degree is selected according to the calculation result; the selected speckle image is printed; the speckle image is cropped according to the size of an object to be detected; the speckle image is arranged on the surface of the object to be detected in a transfer print mode through the transfer print technology, so that the object, to be detected, including the selected speckle image is obtained. The speckle manufacturing method has the advantages of being easy and rapid to manufacture, convenient to operate, high in precision, low in price and wide in application range.

Non-invasive methods for determining blood flow distribution in a region of interest are provided. The method includes illuminating a region of interest of a subject with a coherent light source; sequentially acquiring at least two speckle images of the region of interest, wherein sequentially acquiring the at least two speckle images comprises acquiring the at least two speckle images in synchronization with motion of the heart of the subject; and electronically processing the at least two acquired speckle images based on the temporal variation of the pixel intensities in the at least two acquired speckle images to generate a laser speckle contrast imaging (LSCI) image, determine distribution of blood flow speed in principal vessels and quantify perfusion distribution in tissue in the region of interest from the LSCI image. The LSCI image enables detection of different blood flow speeds.

An image correcting system for deformation measurement of speckle correlation methods is provided. The image correcting system comprises an outer direction mark, a light source, a CCD, a camera support and an image data acquiring and processing device. The outer direction mark is attached to the middle of the plane of a speckle to be measured, the light source is arranged at the front end of a lens of the CCD and is coaxial with the lens, and the CCD is fixed to the camera support and connected with the image data acquiring and processing device. The camera support is used for fixing the CCD and the light source and ensuring the relative fixed position relation. The image data collecting and processing device is connected with the light source and the CCD through wires at the same time. The image correcting system for deformation measurement of speckle correlation methods can conduct initial posture evaluation on the acquired speckle image in the deformation measurement process of the speckle correlation methods, fast identification and locating are conducted on the outer direction marker on the speckle image to be corrected, and the three-dimensional coordinate is resolved, so that the flexibility and speed of strain measurement of the speckle are improved, and reliability of the deformation measurement is improved to a certain degree.

For solving the technical problems that an existing presetting method for a focal plane of a detection camera is more trouble and low in efficiency, and cannot realize presetting of the focal plane ina vacuum environment, the invention provides a presetting device and a presetting method for the focal plane of the detection camera. The presetting device and the presetting method are characterizedin that defocusing distance of the detection camera is converted into that of a star simulator by using the conjugacy relation and the defocusing distance relationship between the star simulator andimaging of the detection camera; confusion spot images, acquired by the detection camera, of the star simulator at different defocusing distances, are analyzed to obtain imaging characteristics of thedetection camera at different defocusing distances, so that motion of a focal plane component of the detection camera is avoided, multiple fixation and adjustment of the posture of the focal plane component of the detection camera are not needed, and the testing efficiency is improved; the detection camera is arranged in a vacuum tank. The imaging characteristics of confusion spots of the detection camera under vacuum conditions are assessed by using the presetting device and the presetting method disclosed by the invention, and further focal plane presetting in the vacuum environment can berealized.

The invention provides a parallax image generation method and system based on binocular stereo vision matching. The parallax image generation method comprises the steps of obtaining a pair of speckleimages, wherein the pair of speckle images are images of speckles captured by an object through a pair of binocularly calibrated cameras under the irradiation of a set light beam; inputting the pair of speckle images into a preset deep learning neural network to generate corresponding parallax images, wherein the deep learning neural network is obtained by training a plurality of pairs of speckleimages. According to the method and the system, a pair of speckle images is used as input, a parallax image is directly output through binocular vision stereo matching network (deep learning neural network) processing, end-to-end calculation of the parallax image and an end-to-end network design framework are realized, post-processing steps of stereo matching, such as sub-pixel enhancement, filtering and noise reduction, refinement and the like, are eliminated, and the operation overhead is greatly reduced.

The invention includes a noninvasive method for characterizing dental pulpal vitality of a tooth including the steps of irradiating the tooth with at least partially coherent light, and speckle imaging to provide quantitative feedback to an end user of pulpal blood flow in the tooth, and the tangible records made by such a method. The invention also includes an apparatus for noninvasively characterizing dental pulpal vitality of a tooth comprising a source of at least partially coherent light for irradiating the tooth characterized by a speckle pattern, optics for directing the at least partially coherent light onto the tooth, including a corresponding pulpal cavity within the tooth, a detector for detecting transmission of the at least partially coherent light through the tooth, and a processor coupled to the detector speckle imaging to provide a quantitative feedback of pulpal blood flow in the tooth.

The invention discloses a method for positioning the mass center of a spatial object star image, which is used for solving the technical problem of low accuracy of the conventional method for positioning the mass center of the spatial object star image. The technical scheme is that: by using a defocused spot imaging mechanism of the spatial object star image and accurately extracting a target area through the energy distribution concentration of the spatial object star image, dependence on a threshold when the target area is extracted by binarization segmentation of a fixed threshold is avoided, and the method has universal applicability; a positioning error which is to be introduced into image background noise is considered, and effective image elements in a target accurate light spot area extracted by concentrated energy distribution are used for gray scale correction, so that mass center positioning accuracy is improved; therefore, the mass center positioning error is improved to 0.08 image element from 0.5 image element in the prior art.

The invention relates to a spectral three-dimensional imaging system and method. The imaging method is characterized by comprising the steps that (1) a three-dimensional laser scanning system acquires three-dimensional information of a plurality of sub regions of a detected target simultaneously and generates a three-dimensional model of targets in each sub region; (2) a rotating platform is used for adjusting the visual field of a spectral imaging system, and the spectral imaging system is aligned to all the scanned sub regions in sequence to acquire spectral images of all the sub regions; (3) a computer control system is used for matching the three-dimensional information of each point in each sub region with the spectral image of the corresponding sub region to generate spectral three-dimensional models of all the sub regions, and finally, the spectral three-dimensional models of all the sub regions are combined to obtain a spectral three-dimensional model of the whole detected target. According to the imaging method, surface three-dimensional information and multispectral information of the target are acquired, and the multispectral information is matched into the three-dimensional model, so that spectral three-dimensional imaging is realized.