941 results about "Phase image" patented technology

A method for three-dimensional shape measurement provides for generating sinusoidal fringe patterns by defocusing binary patterns. A method for three-dimensional shape measurement may include (a) projecting a plurality of binary patterns onto at least one object; (b) projecting three phase-shifted fringe patterns onto the at least one object; (c) capturing images of the at least one object with the binary patterns and the phase-shifted fringe patterns; (d) obtaining codewords from the binary patterns; (e) calculating a wrapped phase map from the phase-shifted fringe patterns; (f) applying the codewords to the wrapped phase map to produce an unwrapped phase map; and (g) computing coordinates using the unwrapped phase map for use in the three-dimensional shape measurement of the at least one object. A system for performing the method is also provided. The high-speed real-time 3D shape measurement may be used in numerous applications including medical science, biometrics, and entertainment.

A radiation phase contrast imaging apparatus, including a radiation emission unit having a plurality of electron sources for emitting electron beams, and a target for emitting radiation through collision of electron beam emitted from each electron source, a first grating in which grating structures for diffracting radiation are disposed periodically, a second grating in which grating structures for transmitting and shielding radiation are disposed periodically, and a radiation image detector for detecting radiation transmitted through the second grating, in which the first and second gratings are disposed in an optical axis direction of the radiation so as to be able to substantially superimpose each image of the first grating formed based on radiation corresponding to each electron source on a surface of the second grating, and the radiation corresponding to each electron source forms each phase image of the same subject on the radiation image detector.

A series of holograms is recorded by synchronizing a camera with laser pulses under the control of a digital delay generator. Amplitude and phase images are calculated while image distances are adjusted for the best focus on the object under observation. The amplitude and phase images are reconstructed while adjusting the image distances over a predetermined range to maintain the object in focus. Numerical superposition of a plurality of holographic fields taken with varying wavelengths provides high resolution microscopic three-dimensional imaging. Numerical reconstruction is based on an angular spectrum method that enables calculation of the image at any distance from the hologram plane. Wavelength scanning digital interference holography also enables image reconstruction along an arbitrarily tilted plane.

A method for tracking coronary artery motion includes constructing (11) a centerline model of a vascular structure in a base phase image in a sequence of 2D images of coronary arteries acquired over a cardiac phase, computing (12), for each pixel in a region-of-interest in each subsequent image, a velocity vector that represent a change in position between the subsequent image and base phase image, calculating (13) positions of control points in each phase using the velocity vectors, and applying (14) PCA to a P×2N data matrix X^T constructed from position vectors (x, y) of N centerline control points for P phases to identify d eigenvectors corresponding to the largest eigenvalues of XX^T to obtain a d-dimensional linear motion model {circumflex over (α)}_p, in which a centerline model for a new image at phase p+1 is estimated by adding {circumflex over (α)}_p to each centerline control point of a previous frame at phase p.

The invention relates to the field of geodetic survey based on remote sensing images, in particular to a method for monitoring roadbed subsidence of express way by an InSAR, which comprises the following steps of: firstly, preprocessing, rectifying and interfering SAR data to obtain an InSAR interfered phase and amplitude image; secondly, carrying out flat earth effect, orographic effect and track residual trend phase elimination on the InSAR interfered phase to obtain a phase value only including surface deformation information; thirdly, recognizing positions and coordinates of strips of the express way in the SAR image by strip characteristics of the express way in the InSAR amplitude image; fourthly, extracting the phase value of the corresponding position in the interfered phase image by using the coordinates, and restoring a real phase value by adopting a filtering and unwrapping algorithm of a strip characteristic target; and fifthly, carrying out geocoding and deformation value transformation on the real phase value to obtain a roadbed subsidence value of the express way. The method has the advantages of simple implementation, low expense, high monitoring precision, large monitoring range, high automation degree and the like.

A stereoscopic visional detecting system based on the adaptive sine fringe projection is composed of computer system, 5D scanning frame, sine fringe projector based on acousto-optic deflector, electric unit, visional sensor and image acquisition unit. When multiple sine rasters are projected onto surface of object, a series of images with different phases is captured by image sensor, then sent to image acquisition unit, and finally processed by computer to obtain the phase diagram about the 3D information of object.

An optical microscope is provided with an adjustable optical phase ring. The adjustable ring provides a way to compensate for distortion in the visible phase ring before the light reaches the sample. In an inverted microscope, when observing transparent cells under a liquid, the visible light phase ring is distorted. By the use of a Liquid Crystal Display (LCD) in place of a fixed ring, the projected ring is adjusted to realign the light and produce phase. In a typical micro plate, the meniscus formed produces a lens effect that is realigned by providing changes in the position and pattern, to allow phase imaging over a wider portion of the well. The realignment of the ring can be manual or automated and can be dynamically adjusted based upon an observed image of the sample.

A three-dimensional mirror object shape measurement system based on sinusoidal stripe projection mainly comprises a computer system, a sinusoidal stripe projection system based on an acousto-optic deflector, an image acquisition system, a quick positioning system and a precise translation stage. A computer controls the sinusoidal stripe projection system to project a plurality of sinusoidal stripes to a directly measured surface of a mirror object, the phase, the frequency and the brightness of each projected sinusoidal stripe are adjustable, then the image acquisition system acquires corresponding image information and transmits the image information to the computer system, the computer system processes the image information, accordingly, a phase image containing three-dimensional information of the object is obtained, and finally, three-dimensional information of the measured surface of the mirror object is obtained according to a phase and height mapping relation. The three-dimensional mirror object shape measurement system is mainly applied to three-dimensionally measuring shapes of micro-sized mirror objects, the measurement range is about 4.5mmX3mm, the resolution is superior to 5 micrometers, and three-dimensional point cloud space is 3.75 micrometers.

The invention relates to a heterodyne three-frequency unequal range phase displacement solution phase method, and the method is as follows: selecting three frequencies, firstly adopting four-step phase shift method to obtain the package phase and average light intensity of the middle frequency, adopting two-step phase shift method to obtain the package phase corresponding to the two frequencies under the condition with known light intensity, obtaining the true phase according to the heterodyne method, adopting the contour line sine and cosine filtering method in the optical grating projection three-dimensional measurement, using stripe direction information for filtering the package phase on isophasal line, the method uses less projection picture for exactly measuring and uses the stripe direction information for filtering the package phase picture for effectively removing the inconsistent points in the package phase picture, the heterodyne three-frequency unequal range phase displacement solution phase method is used in the phase method three-dimensional shape measurement for effectively raising the measuring efficiency and measuring accuracy.

Hilbert phase microscopy (HPM) as an optical technique for measuring high transverse resolution quantitative phase images associated with optically transparent objects. Due to its single-shot nature, HPM is suitable for investigating rapid phenomena that take place in transparent structures such as biological cells. A preferred embodiment is used for measuring biological systems including measurements on red blood cells, while its ability to quantify dynamic processes on the millisecond scale, for example, can be illustrated with measurements on evaporating micron-size water droplets.

An image processor (101) according to a preferred embodiment of the present invention includes a polarized light source (102) and a polarization camera (103). In shooting an object (104), the object is irradiated with polarized light (105) that rotates its polarization plane. The polarized light is reflected from the object's surface and the polarized reflected light (106) reaches the polarization camera (103), thereby recording an image there. The polarization camera (103) includes a polarization image sensor (201), an intensity and polarization information processing section (202), a polarization plane control section (204), and an image capturing control section (205). By capturing an image every time the polarization plane control section (204) changes the polarization state of the polarized light, an intensity image Y and a polarization phase image P are obtained in association with each polarization state. Using these images, a resolution increasing processing section (203) generates a high-resolution normal image (208) and a high resolution intensity image (209).

The present invention discloses a method to improve the image resolution of a microscope. This improvement is based on the mathematical processing of the complex field computed from the measurements with a microscope of the wave emitted or scattered by the specimen. This wave is, in a preferred embodiment, electromagnetic or optical for an optical microscope, but can be also of different kind like acoustical or matter waves. The disclosed invention makes use of the quantitative phase microscopy techniques known in the sate of the art or to be invented. In a preferred embodiment, the complex field provided by Digital Holographic Microscopy (DHM), but any kind of microscopy derived from quantitative phase microscopy: modified DIC, Shack-Hartmann wavefront analyzer or any analyzer derived from a similar principle, such as multi-level lateral shearing interferometers or common-path interferometers, or devices that convert stacks of intensity images (transport if intensity techniques: TIT) into quantitative phase image can be used, provided that they deliver a comprehensive measure of the complex scattered wavefield. The hereby-disclosed method delivers superresolution microscopic images of the specimen, i.e. images with a resolution beyond the Rayleigh limit of the microscope. It is shown that the limit of resolution with coherent illumination can be improved by a factor of 6 at least. It is taught that the gain in resolution arises from the mathematical digital processing of the phase as well as of the amplitude of the complex field scattered by the observed specimen. In a first embodiment, the invention teaches how the experimental observation of systematically occurring phase singularities in phase imaging of sub-Rayleigh distanced objects can be exploited to relate the locus of the phase singularities to the sub-Rayleigh distance of point sources, not resolved in usual diffraction limited microscopy. In a second, preferred embodiment, the disclosed method teaches how the image resolution is improved by complex deconvolution. Accessing the object's scattered complex field—containing the information coded in the phase—and deconvolving it with the reconstructed complex transfer function (CTF) is at the basis of the disclosed method. In a third, preferred embodiment, it is taught how the concept of “Synthetic Coherent Transfer Function” (SCTF), based on Debye scalar or Vector model includes experimental parameters of MO and how the experimental Amplitude Point Spread Functions (APSF) are used for the SCTF determination. It is also taught how to derive APSF from the measurement of the complex field scattered by a nanohole in a metallic film. In a fourth embodiment, the invention teaches how the limit of resolution can be extended to a limit of λ/6 or smaller based angular scanning. In a fifth embodiment, the invention teaches how the presented method can generalized to a tomographic approach that ultimately results in super-resolved 3D refractive index reconstruction.

Provided are a device for measuring fractional-order optical vortex topology charge values and a measuring method thereof. The measuring method comprises the steps of writing generated calculating holographic images into a spatial light modulator through a computer holographic technique, acquiring wrapped phase images of vortex light beams through Michelson interference light paths and a four-step phase shifting technique, analyzing distribution of real phases theta of the vortex light beams through a phase image unwrapping algorithm, and calculating according to the topology charge definition of m=theta/2pi to obtain topology charge values m of any fractional-order accuracy. The device and method achieve the measurement of any step (0.1 step) of topology charge values of the fractional-order vortex light beams, can correct measurement of topology charge values of vortex light beams from existing half-integer step (0.5 step) to any step and can be widely applied to measurement of topology charge values in the fields of bose-einstein condensation, quantum communication, information coding and transmission, particle confinement, optical tweezers, optical wrenches and the like.

The present invention relates to systems and methods for medical imaging. Digital images are processed to provide phase images of a region of interest to aid in the diagnosis and treatment of various conditions. A preferred embodiment of the invention provides improved mammography screening for cancerous or precancerous conditions.

A phase retrieval method for differential phase contrast imaging includes receiving data corresponding to a differential phase image generated from a measured signal. The measured signal corresponds to an X-ray signal detected by a detector after passing through a subject located with a grating arrangement between an X-ray source and the detector. The method further includes generating a phase image corresponding to the integration of the differential phase image. Generating the phase image includes performing an iterative total variation regularized integration in the Fourier domain.

The invention provides a medical image analysis method, a medical image analysis system and a medical device. The method comprises the following steps that: a plurality of paths of image data are imported; the spatial coordinate positions of the imported different paths of image data are registered, and registration relations are established; one or more paths of image data are selected, and one or more target regions are separated from each path of image data; the features of the target regions are extracted, and the target regions are mapped into other images according to the registration relations; any spatial plane position is specified, a plurality of section images are generated according to the registered images; and different section position image are correspondingly displayed in different sub-windows, and the same section position images from different image data are displayed in the same sub-windows. With the method of the invention adopted, the technical problems of incapability of embodying the volumetric characteristics of three-dimensional image data and being adverse to the comparison of the differences of different images of a display mode in the prior art can be solved, the subtle differences of images of the same mode or different modes and spatial corresponding position relations of target tissue structures in different modes and time-phase images can be fast and effectively observed, and therefore, image contrast analysis can be facilitated.

The invention discloses a time phase unwrapping method based on double frequency three-gray-scale sinusoidal grating fringe projection. The method comprises the steps that two sets and five ideal double-frequency sinusoidal grating fringes are generated by utilizing a computer, then three-gray-scale sinusoidal grating fringes corresponding to the ideal double-frequency sinusoidal grating fringes are generated by adopting the three-gray-scale space pulse width modulation technology, under condition that that a projector keeps the defocusing state, the five three-gray-scale sinusoidal grating fringes are projected to the surface of an object to be measured, two sets of wrapped phase images are solved, wherein the five double-frequency fringes comprise the two sets of wrapped phase images, the fringe order corresponding to the wrapped phase is solved, and unwrapping of the wrapped phase is achieved. The time phase unwrapping method based on the double frequency three-gray-scale sinusoidal grating fringe projection improves measurement precision and measurement speed.

A system and method for MR magnetic field mapping includes a computer programmed to acquire a first data point at a first location in a first phase image data set, a second data point at the first location in a second phase image data set, a third data point at the first location in a third phase image data set. The first, second, and third phase images are acquired using a first, second, and third TE, respectively. Phase wrapping does not occur among the first and second phase image data sets; however, phase wrapping does occur among the second and third phase image data sets. The computer is also programmed to determine a magnetic field inhomogeneity, wherein the determination of the magnetic field inhomogeneity is based on the first, second, and third data points.

For correcting differential phase image data 52, differential phase image data 52 acquired with radiation at different energy levels is received, wherein the differential phase image data 52 comprises pixels 60, each pixel 60 having a phase gradient value 62a, 62b, 62c for each energy level. After that an energy dependent behavior of phase gradient values 62a, 62b, 62c of a pixel 60 is determined and a corrected phase gradient value 68 for the pixel 60 is determined from the phase gradient values 62a, 62b, 62c of the pixel 60 and a model for the energy dependence of the phase gradient values 62a, 62b, 62c.

A cotton developmental phase automatic identification method based on image classification and target detection belongs to the field of agricultural meteorological observation. With development of image processing and deep learning technologies, transformation of agricultural meteorological observation mode from manual observation to automatic observation becomes possible. In order to realize automatic observation for a cotton developmental phase, the invention provides a cotton developmental phase automatic identification method based on image classification and target detection. In method provided by the scheme, different features existing in each developmental phase image are observed and analyzed, then, automatic identification of a three true leaves phase, a five true leaves phase anda squaring phase is realized through image classification based on deep learning, further, flowers and cotton fiber in the image are detected automatically through deep target detection, and finally,results of two algorithms are integrated, and automatic identification for a complete cotton developmental phase is realized. The method provided by the scheme can realize rapid and accurate automatic identification for the cotton developmental phase and has very important application value.

A method converts an input image of noisy wrapped phases to an output image of absolute unwrapped phases. The noisy wrapped phases in the input image are represented as a set of re-wrapped phases and a set of phase shifts. The set of re-wrapped phases are partitioned into a first group and a second group. Integer differences between the phase shifts are optimized while holding the re-wrapped phases fixed. Then, the first group of re-wrapped phases are optimized, while holding the integer differences between the phase shifts, and the second group of re-wrapped phases fixed. The integer differences between the phase shifts are optimized again, while holding the re-wrapped phases fixed. Then, the second group of re-wrapped phases are optimized, while holding the integer differences between the phase shifts, and the first group of re-wrapped phases fixed. The optimizing steps are repeated until the re-wrapped phase converge. Then, the converged re-wrapped phases and integer differences between the phase shifts are output as an output image of absolute unwrapped phases.