63 results about "Numerical reconstruction" patented technology

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 of imaging an object, such as a diseased human heart or bone, in a nontransparent medium, such as the human body, involves placing an array of transmitters and receivers in operational association with the medium. The transmitters generate a harmonic (frequency domain) or pulse (time domain) primary electromagnetic field (EM) which propagates through the medium. The primary field interacts with the object to produce a scattered field, which is recorded by the receivers. The scattered EM field components measured by the receivers are applied as an artificial EM field to generate a backscattering EM field. Cross power spectra of the primary and backscattering fields (in the frequency domain) or cross correlation between these fields (in the time domain) produce a numerical reconstruction of an EM hologram. The desired properties of the medium, such as conductivity or dielectric permittivity, are then derived from this hologram.

The present invention provides for a digital holographic microscope using a holographic interferometer and incorporating a TIR sample mount and microscopic imaging optics. The microscope uses phase shifting from frustrated internal reflection within a prism to measure nanometric distances. The invention also provides for a numerical reconstruction algorithm of an inclined surface of the object / prism.

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.

The invention relates to a two-dimensional image and multi-point statistics-based digital core reconstructing method. The method disclosed by the invention comprises the steps of obtaining a two-dimensional training image of a rock sample by using a physical experiment method; and by combining with a multi-point statistical method, obtaining high-order statistical information on the two-dimensional core image on the basis of the obtained two-dimensional core image, thereby constructing a three-dimensional digital core which can reflect true inner-pore structural features of the core. By meansof the method, the shortcomings caused by only applying a two-point statistical function in a traditional numerical reconstruction algorithm are overcome.

A method of security screening and inspection of people in airlines, ships, or secured buildings, involves placing an array of transmitters and receivers in operational association with the medium. The transmitters generate a broad band harmonic (frequency domain) or pulse (time domain) primary electromagnetic field (EM) field, including the lower frequency portions of the EM spectrum, whose propagation is typically characterized by the diffusion phenomena, or by the combination of the diffusion and wave phenomena. The primary field propagates through and interacts with the examined person and any objects carried by the person to produce a scattered field, which is recorded by the receivers. The scattered EM field components measured by the receivers are applied as an artificial EM field to generate a backscattering EM field. Cross power spectra of the primary and backscattering fields (in the frequency domain) or cross correlation between these fields (in the time domain) produce a numerical reconstruction of an EM hologram. The desired properties of the person, including the properties of any objects carried by the person, such as conductivity or dielectric permittivity, are then derived from this hologram.

The invention relates to an on-line digital holographic imaging reconstruction display system and method. According to the system and the method, a reconstruction imaging process can be orderly displayed by steps and selectively displayed. The system comprises an off-axis fresnel digital holographic recording light path, an instrument control unit and an imaging reconstruction display unit. The off-axis fresnel digital holographic recording light path is employed to record a digital hologram on an image collector under the control of the instrument control unit; the imaging reconstruction display unit is used for numerically simulating a diffraction imaging process of the digital hologram by a numerical reconstruction algorithm, performing operation prompting for a user through a human-machine interaction interface, receiving instruction input, displaying data, and displaying an image of each stage in the digital holographic imaging reconstruction process step by step on line; and therefore, imaging reconstruction of an original object is realized.

A method for tracking particles and life forms in three dimensions and in time. The present invention applies a numerical reconstruction approach to digital in-line holographic microscopy images in order to generate a time sequence hologram representing the trajectory of objects such as particles and life forms. By subtracting consecutive (in time) holograms of a particle sample volume and then adding the resulting differences, a final hologram is constructed that contains the time evolution of the object trajectory free from spurious background interference effects.

A method of security screening and inspection of people in airlines, ships, or secured buildings, involves placing an array of transmitters and receivers in operational association with the medium. The transmitters generate a broad band harmonic (frequency domain) or pulse (time domain) primary electromagnetic field (EM) field, including the lower frequency portions of the EM spectrum, whose propagation is typically characterized by the diffusion phenomena, or by the combination of the diffusion and wave phenomena. The primary field propagates through and interacts with the examined person and any objects carried by the person to produce a scattered field, which is recorded by the receivers. The scattered EM field components measured by the receivers are applied as an artificial EM field to generate a backscattering EM field. Cross power spectra of the primary and backscattering fields (in the frequency domain) or cross correlation between these fields (in the time domain) produce a numerical reconstruction of an EM hologram. The desired properties of the person, including the properties of any objects carried by the person, such as conductivity or dielectric permittivity, are then derived from this hologram.

A method for identifying a particle contained in a sample, including illuminating the sample using a light source, the light source producing an incident light wave propagating toward the sample, then acquiring, using a matrix-array photodetector, an image of the sample, the sample being placed between the light source and the photodetector such that the matrix-array photodetector is exposed to a light wave that is the result of interference between the incident light wave and a diffraction wave produced by each particle. The method further includes applying a numerical reconstruction algorithm to the image acquired by the photodetector, to estimate a characteristic quantity of the light wave reaching the detector, at a plurality of distances from the detector. The variation in the characteristic quantity as a function of distance allows the particle to be identified.

A method for identifying a state of a cell contained in a sample, including: illuminating the sample using a light source by producing an incident light wave propagating toward the sample; then acquiring, using a matrix-array photodetector, an image of the sample, the sample being placed between the light source and the matrix-array photodetector such that the matrix-array photodetector is exposed to a light wave resulting from interference between the incident light wave and a diffraction wave produced by each cell; applying a numerical reconstruction algorithm to the image acquired by the matrix-array photodetector, to estimate a characteristic quantity of the light wave reaching the matrix-array detector, at a plurality of distances from the matrix-array photodetector. The value of the characteristic quantity, or its variation as a function of distance, allows the state of the cell to be determined from among predetermined states.

The present invention discloses a high resolution holographic microscope and a method for living cell imaging, and belongs to the technical field of holographic microimaging. In a holographic opticalpath, when a secondary point light source passes through a living cell sample, diffracted object light interferes with undiffracted reference light to form an in-line hologram; the image is magnifiedby a high power microobjective, received by a CCD camera and stored in a computer; and a reconstructed image is obtained by computer numerical reconstruction. The invention uses a low power microobjective to convert a parallel light source into the secondary point light source combined with the object light and the reference light in the same direction during a recording process, makes full use ofa limited spatial bandwidth of the CCD camera, greatly improves the resolution of the holographic microscope system, uses a three-dimensional micron-scale displacement platform to precisely adjust the microscopic resolution and receives more interference outer ring fringes by shortening the recording distance, which includes high-frequency information of the sample playing a key role in reconstructing the image. Combined with the high power microobjective in front of the CCD camera, non-contact, non-invasive, fast, quantitative and high-resolution holographic microimaging of the living cell sample can be realized.

The invention discloses a method and system for measuring a polarization state of a sample based on a polarization beam splitting prism. After light emitted by a laser device is aligned through an alignment device, the light is split into two beams through a non-polarization beam splitting prism, wherein one beam of light penetrates through a sample or carries sample information after being reflected by the sample and is used as an object light beam; the other beam of light is used as a reference light beam; the two beams of light are reflected through a reflecting mirror and then are converged through the non-polarization beam splitting prism. The polarization beam splitting prism is rotated so that the reference light beam is divided into two beams of linearly polarized light, which havebasically equal light intensity and crossed polarization directions, after passing through the polarization beam splitting prism. After the reference light beam and the object light beam pass throughthe polarization beam splitting prism, two interference patterns with orthogonal polarization states are formed. Two holograms are recorded by utilizing a camera. A computer is used for further carrying out numerical value reconstruction on complete unification positions and corresponding pixel points of the sample in the two holograms; finally, corresponding amplitude and phase information of anobject light wave field is finally obtained; the information is processed by the computer to obtain polarization state information of the sample. Compared with utilization of a traditional Mueller microscope, a condition that a plurality of times of acquisition are influenced by the environment is avoided and the stability and the real-time measurement capability of the system are improved.

The invention discloses a measuring method of material electrostrictive strain and distribution thereof based on digital holographic interferometry. The method comprises steps: applying an electric field on a tested material, recording digital holograms in different electric fields, performing numerical reconstruction, to obtain phase distribution; using a digital holographic interference technology, to obtain phase difference distribution under different states, through strain relations, calculating to obtain strain and distribution of materials; plotting points of corresponding strain values in different electric field to draw, to obtain an electrostrictive strain curve of the material, so as to obtain an inverse piezoelectric coefficient of the material. Compared with the prior art, a non-contact measuring method is used, and the method is characterized by simple principle, convenient measuring, low cost, high precision, and good practicality, and can dynamically measure strain distribution of a whole material surface in real time.

The invention discloses a landslide process analysis method, a process numerical reconstruction method and application. According to the landslide disaster process analysis method, an IMF main component signal is extracted on the basis of an original landslide ground motion signal, time-frequency spectrum transformation is carried out, and then five stages of a landslide process are divided according to frequency energy characteristics of different time periods in the landslide ground motion signal. The method extracts the transition stage of the landslide process for the first time. The invention provides application of a landslide disaster process analysis method in landslide disaster analysis, landslide disaster emergency response scheme design and landslide event mathematical modeling.The invention further provides a numerical simulation reconstruction method for the landslide process, and numerical simulation reconstruction of the landslide process is carried out on the basis ofenergy data evolution of the landslide ground motion signals. The invention further discloses application of the reconstruction method in landslide disaster analysis and landslide disaster emergency response scheme design. According to the method, the basic data richness of landslide disasters and the effectiveness of disaster prevention and control emergency schemes are improved, and the invention has remarkable social benefits.

The invention discloses a non-paraxial and defocusing aberration numerical correction method. Firstly, a hologram recording distance is defined as d. The non-paraxial aberration correction and the defocusing aberration correction are carried out for a non-lens Fourier transformable digital hologram . The corrected hologram is carried out with IFFT to obtain a numerical reconstruction image. A numerical focusing plane is judged to define an optimal correction distance d' and an optimal reconstruction distance d '. The d'is taken as d and is substituted into a non-paraxial aberration correction factor, and the hologram is again carried out with the non-paraxial aberration correction. The d' is substituted into a correction distance D of the defocusing aberration correction factor, and the hologram is again carried out with the non-paraxial aberration correction. The corrected hologram is carried out the IFFT and then the ideal hologram numerical reconstructed image without aberration is obtained.

The invention provides a sample rod for a transmission electron microscope system. The sample rod is characterized in that the sample rod (12) comprises a front end head and a sample rod body, the first end of the front end head is connected with the sample rod body, a sample is installed at the second end of the front end head, and an optical fiber (21) which extends from one end of the sample rod body to the other end of the sample rod body and faces the sample on the front end head is arranged in the sample rod body. According to the transmission electron microscope system provided by the invention, firstly, laser is divided into object light waves and reference light waves through a polarization splitting prism; the object light waves and the reference light waves are subjected to off-axis interference at the image acquisition device after passing through the optical fiber of the sample rod, conjugate phase information of the object light waves is obtained through numerical reconstruction and is loaded to a spatial light modulator, time reversal of the light waves is realized, and laser focusing and automatic scanning of the light waves are realized in the transmission electronmicroscope system.

A method for identifying a state of a cell contained in a sample, including: illuminating the sample using a light source by producing an incident light wave propagating toward the sample; then acquiring, using a matrix-array photodetector, an image of the sample, the sample being placed between the light source and the matrix-array photodetector such that the matrix-array photodetector is exposed to a light wave resulting from interference between the incident light wave and a diffraction wave produced by each cell; applying a numerical reconstruction algorithm to the image acquired by the matrix-array photodetector, to estimate a characteristic quantity of the light wave reaching the matrix-array detector, at a plurality of distances from the matrix-array photodetector. The value of the characteristic quantity, or its variation as a function of distance, allows the state of the cell to be determined from among predetermined states.

The invention relates to the technical field of computer vision, and particularly discloses a low-redundancy rapid reconstruction method for a plankton hologram comprising the following steps: S1, collecting a plankton digital hologram, and generating a source image data set; S2, calibrating plankton in each holographic source image in the source image data set to obtain a calibration data set; S3, training the established hologram reconstruction network by using the calibration data set, and testing the trained hologram reconstruction network by using the source image data set; and S4, using the tested hologram reconstruction network for reconstruction of other plankton holographic source images. The hologram reconstruction network can automatically detect an effective target area and reconstruct an area of interest. Compared with a traditional numerical reconstruction method, the hologram reconstruction network trained by the method is high in plankton hologram reconstruction speed and high in redundant information elimination efficiency, and is expected to play an important role in marine environment detection.

The present invention discloses a design method of a concrete block cooling system based on a fast and accurate numerical reconstruction technology, which takes the water pipe cooling effect in the concrete block as a negative heat source of the system, and takes the influence of cement hydration heat into account. The method comprises: configuring a plurality of test points inside and at the boundary of the inspected concrete block to obtain temperature values of the test points; establishing the equivalent control equation for the heat conduction problem, and obtaining a plurality of local low-order matrices according to the radial basis function collocation method; calculating shape parameters of the radial basis function by using the multi-scale algorithm; using the matrix sparse algorithm to construct the equation required by calculating the temperature field; calculating the temperature value of any inner point at any time; and determining the rationality of the cooling system scheme according to the maximum temperature difference between the inside and outside of the inspected structure. The method of the present invention is simple and efficient, and has the characteristicsof high precision, fast calculation, simple mathematics and a simple procedure; and the method conforms to the characteristic requirements of a fast, stable and accurate data reconstruction technology which is required in the design of the concrete block cooling system.

The invention relates to a method for efficiently measuring the polarization state and the phase of an arbitrary beam at the same time and an optical path. Based on the geometric phase theory, a method for simultaneously measuring the polarization state and the phase of an arbitrary beam and an optical path for realizing the method are proposed. During the measurement process, only two interferograms are acquired at the same time. By holographic numerical reconstruction of the interferograms and extraction of phase and amplitude information, the polarization and phase distribution of the measured beam can be calculated. The method can be used not only to measure the polarization state and the phase distribution of an arbitrary beam, but also to detect a polarization optical element.

The invention provides a microplastic detection device and method based on a ratio of a three-dimensional contour chain code to a bright spot perimeter. The device includes a light source assembly, alight through hole assembly, a light propagation assembly, a microfluidic chip, an image acquisition assembly, and an image processing assembly that are connected successively. According to the method, a coaxial lensless digital holographic microscope system records a microplastic holographic image; numerical reconstruction is carried out on the holographic image to restore a three-dimensional real morphology in a microplastic sample; with the three-dimensional real morphology, a three-dimensional contour corresponding to the microplastic maximum diameter is obtained, a slope between adjacentpixels at the contour is calculated, and the slope is converted into a 8-chain code; and the microplastics is detected and distinguished by calculating a ratio of a slope chain code string sum to theperimeter of the bright spot at the center of the hologram. According to the invention, the microplastic detection device has characteristics of simple structure, high portability and simple operation. Problems of difficult detection of microplastics, complicated device structure, and inconvenient use in the prior art are solved.

A method for identifying a particle contained in a sample, including illuminating the sample using a light source, the light source producing an incident light wave propagating toward the sample, then acquiring, using a matrix-array photodetector, an image of the sample, the sample being placed between the light source and the photodetector such that the matrix-array photodetector is exposed to a light wave that is the result of interference between the incident light wave and a diffraction wave produced by each particle. The method further includes applying a numerical reconstruction algorithm to the image acquired by the photodetector, to estimate a characteristic quantity of the light wave reaching the detector, at a plurality of distances from the detector. The variation in the characteristic quantity as a function of distance allows the particle to be identified.

The invention discloses a multi-mode microscopic image numerical reconstruction method, which comprises the following steps of: firstly, illuminating a sample by using K different structured lights, and sequentially shooting Fourier spectrum bright spots of light waves of a sample object to obtain K digital Fourier spectrum images; secondly, encoding each Fourier spectrum image by using the digital mask plate matrix to obtain a corresponding encoded spectrum image matrix; summing all matrix element integrals of each coded spectrum image matrix to obtain K Fourier spectrum integral values; carrying out image reconstruction on the K Fourier spectrum integral values, and a digital image obtained through reconstruction being a microscopic image of one mode; and finally, carrying out numericalreconstruction of microscopic images in different modes by using the Fourier spectrum image, and finally, obtaining microscopic images in multiple modes and differential phase contrast microscopic images in one or more modes. According to the method, microscopic images in various different modes can be obtained very flexibly through numerical reconstruction, and the method has important application value.

The invention provides a novel multi-wavelength phase microscopic imaging method based on an F-P cavity. The method is characterized by comprising the steps of F-P cavity-based multi-wavelength digital hologram recording, numerical reconstruction, unwrapping, error processing, three-dimensional phase distribution reconstruction and three-dimensional refractive index conversion. The invention mainly provides a novel multi-wavelength phase microscopic imaging method based on an F-P cavity, and the method is higher in sensitivity compared with a conventional microscopic imaging method. The mehtodhas the advantages of being simple in structure, high in sensitivity and accurate in measurement. The method can be used for high-resolution three-dimensional microscopic imaging of an optical transparent object, and can be widely applied to lossless, unmarked and non-contact three-dimensional tomography and the like of tiny organisms.

The invention provides a new three-dimensional test method for a common-optical-path F-P cavity enhanced cell absorptivity. The method is characterized by comprising digital hologram recording based on an F-P cavity, numerical reconstruction, error processing and three-dimensional absorptivity distribution reconstruction. The invention mainly provides a new three-dimensional test method for the common-optical-path F-P cavity enhanced cell absorptivity, and compared with a traditional microscopic imaging method, the new three-dimensional test method has higher sensitivity. The method provided by the invention has the advantages of simple structure, high sensitivity and precise measurement. The method can be used for high-resolution three-dimensional microscopic imaging of biological cells,and can be widely applied to nondestructive, label-free and non-contact three-dimensional tomography and the like of optical transparent objects.

The invention discloses a numerical reconstruction method for a residual stress field of a surface strengthening metal part. Based on commercial CAE-based software, compression stress is generated inthe reinforced layer region by using the temperature difference. Different temperature values are set for a material or a component strengthening layer and other areas respectively, so that residual compressive stress fields generated by different surface strengthening processes are simulated. Adjustment is carried out according to actually-measured component residual stress data.The residual compressive stress fields are matched with the residual stress gradient distribution of the actually-measured data and subsequent numerical simulation calculation is facilitated. According to the method,a relatively accurate result can be obtained, the universality is high, the efficiency is high, the economical efficiency is good, the simulation and design process is greatly simplified, and a residual compressive stress field conforming to actual measurement data can be rapidly and economically deduced in engineering application.

The invention relates to an external common-optical-path off-axis digital holographic microimaging device. The device sequentially comprises a one-dimensional periodic grating, a fourth lens, a filterand an imaging detector in the optical path direction. Parallel light beams carrying object information are diffracted after passing through the one-dimensional periodic grating, and on the Fourier spectrum surface of the fourth lens, zero-level diffracted light and + 1-level diffracted light filtered by a filter are adopted to generate an off-axis hologram on the target surface of the imaging detector, and the off-axis hologram is recorded by the imaging detector. The off-axis hologram is reconstructed by adopting a well-known numerical reconstruction algorithm in the field of digital holography to obtain the phase information of the measured object. The device is simple and compact in structure and convenient to install and adjust, can be directly used as external equipment of a commercial optical microscope to carry out quantitative microscopic imaging on micro-nano structure objects such as biological cells, and has a very strong market application prospect.

The invention discloses a large-area uniform illumination system based on aspheric lens surface shape numerical reconstruction, and belongs to the technical field of non-imaging optics and extended light source beam shaping. The system comprises a plurality of array units which are arranged at equal intervals in a row direction and a column direction and have the same structure. Each array unit iscomposed of an aspheric lens (U) and a light-emitting surface light source (V). The aspheric lens surface type parameters of all the aspheric lenses (U) are the same, and all the light-emitting surface light sources (V) are the same; the optical axis of each light-emitting surface light source coincides with the optical axis of the corresponding aspheric lens, light emitted by the light-emittingsurface light sources is deflected by the corresponding aspheric lenses to generate corresponding energy distribution units on a target lighting surface, and all the energy distribution units are overlapped to generate preset large-area uniform energy distribution. The system is compact and simple in structure; the illumination area is large, the energy distribution uniformity is high, and the energy utilization rate is high; practicability is high, and the application range is wide.