191 results about "Point spread" patented technology

When utilized in a flow imaging instrument, calibration beads provide a known data source that can be employed in various self-diagnostic, calibration and quality metric applications for the both the optical system of the flow imaging instrument, as well as the flow cell of the flow imaging instrument. Such data can be used to determine point spread functions associated with an imaging system, to determine a sensitivity of an imaging system, and to determine a focal point of the imaging system. Imagery collected from calibration beads can be used to determine core size and stability and TDI/flow speed synchronization. Calibration beads can be beneficially employed to enable stable system operation, even when very low sample concentration, or very small sample sizes are to be analyzed.

An extended depth of field is achieved by a computational imaging system that combines a multifocal imaging subsystem for producing a purposefully blurred intermediate image with a digital processing subsystem for producing a recovered image having an extended depth of field. The multifocal imaging system preferably exhibits spherical aberration as the dominant feature of the purposeful blur. A central obscuration of the multifocal imaging subsystem renders point-spread functions of object points more uniform over a range of object distances. An iterative digital deconvolution algorithm for converting the intermediate image into the recovered image contains a metric parameter that speeds convergence, avoids stagnations, and enhances image quality.

Embodiments of the invention describe a method for reducing a blur in an image of a scene. First, we acquire a set of images of the scene, wherein each image in the set of images includes an object having a blur associated with a point spread function (PSF) forming a set of point spread functions (PSFs), wherein the set of PSFs is suitable for null-filling operation. Next, we invert jointly the set of images and the set of PSFs to produce an output image having a reduced blur.

The invention, which belongs to the wireless positioning field, relates to an indoor positioning method for receiving a signal strength ordering fingerprint. The method comprises the following steps that: the number of sampling points spreading in a whole positioning area is determined; sampling point traversal is carried out, received signal strength indicator (RSSI) values of signal strengths of k wireless access points (AP) are obtained by detection at each sampling point, and arrangement is carried out to obtain an RSSI sequence, wherein each RSSI corresponds to one MAC address and the RSSI sequence ad the MAC addresses form sampling point position fingerprints jointly; the coordinates and the position fingerprints of the sampling points are stored into a fingerprint database; AP scanning is carried out at an unknown position to obtain a position fingerprint of an unknown position C and the MAC address sequence in the position fingerprint of the position C is matched with MAC address sequences of the position fingerprints of all sampling points in the fingerprint database; and a geographical coordinate corresponding to the sampling point with consistent matching is used as the current position of the unknown position C a. According to the invention, relative sequences of RSSIs of different APs are used as fingerprints and thus a positioning error caused by different RSSI absolute values by different wireless terminal scanning can be avoided.

A transmission/reception beamformer output provided with point spread functions having different wave number vector directions is used to obtain a compound image that is highly isochronous and sufficiently blurring-resistant.

The invention discloses a local three-dimensional matching method based on credible point spreading. The local three-dimensional matching method includes: a, at least calculating minimum values and second minimum values of matching cost of pixel points under different parallax hypothesis by utilizing an AD (absolute intensity differences)-Census algorithm, and obtaining a DSCI image by combining with gradient information of images; b, obtaining initial disparity maps of the images according to the DSCI; c, dividing the pixel points into credible points, unlikelihood points and shielding points, wherein the credible points are determined by combining with the minimum values and the second minimum values to the matching cost; d, calculating the disparity values of the credible points and processing the unlikelihood points and the shielding points through the credible points to obtain the disparity values; and e, outputting a disparity image. The local three-dimensional matching method based on the credible point spreading effectively utilizes data in an initial disparity image, enables the credible points to be determined reasonably and accurately, further enables the following processing on the unlikelihood points and the shielding points to be accurate and finally ensures the accuracy of the matching method.

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.

The invention relates to the field of disaster information management, in particular to a method for establishing a flood disaster geographical analysis and evaluation dynamic model. The method includes the steps that initial data of a region to be analyzed are collected, compressed and then stored in an established lightweight class spatial database; the initial data are retrieved, an established flood inundation analysis model is initialized, and a final flood inundated region areal map and a water depth classification map are acquired through a seed point spreading algorithm; integrated data of the final flood inundated region areal map and the water depth classification map are input to a flood disaster loss evaluation mathematical model and a flood risk evaluation mathematical model for calculation, and then the economic loss condition and the potential flood-hit risk degree of villages in a flood storage and detention region after flood inundation are acquired. A spatial database system and the flood inundation analysis model which are excellent in performance and stable and reliable in operation are established, the organization and management method of image raster data is optimized, the flood inundation condition of the flood storage and detention region under a given condition is visually displayed, and the consequential loss evaluation function is provided.

An image-capturing unit generates an image signal corresponding to an image of a subject formed by a photographing optical system. A point spread function generating unit generates varying point spread functions corresponding to various distances based upon two-dimensional distance distribution information indicating the two-dimensional distance distribution of the subject detected by a distance detection unit and an image blur signal indicating an image blur occurring during the exposure period which is detected by a blur detection unit. An image repair unit divides the image signal into partial images based upon the distance distribution information, executes image processing to repair the blur in the individual partial images by using the point spread functions corresponding to the various distances and creates a whole image by synthesizing the partial images in which the blur has been repaired.

A magnetic resonance method and system are provided for providing improved multi-band (MB) magnetic resonance imaging. The adaptive MB imaging can be achieved by providing one or more modified multi-band excitation pulse sequences that include at least either one nullified “dummy” slice within a slab that is not excited simultaneously with the other slices during a single multislice acquisition sequence, or one excitation slice group that utilizes a non-uniform slice spacing between simultaneously excited slices. Adaptive GRAPPA or slice-GRAPPA kernel sizes can also be used during image reconstruction to improve speed without excessive point spread blurring or MB reconstruction failure. A total leakage factor (TLF) can also be determined based on test images using modified MB excitation sequences, and used to improve the adaptive MB procedure.

Systems and methods analyze, diagnose, and/or treat a patient's eye using modified forms of the point spread function (“PSF”) tailored to the vision system. Factors that alter perception of visual aberrations can be included and/or volumetric point spread functions calculated, often using point spread function calculations throughout a range of optical distances to more fully indicate the variation in visual perception of optics at different distances. A variety of visual affects of the human optical system can be simulated, analyzed, and modeled, including: single versus multiple wavelength sources, chromatic aberrations, retinal resolution, wavelength-dependent visual response, Stiles-Crawford effects, and/or non-linearity of retinal response. The perceived point spread function can offer objective confirmation of the patient's visual perception, allow a treating physician to see a closer approximation of what the patient sees, indicate the scale and significance of wavefront aberrations, and/or show which aberrations affect vision and which do not.

The invention discloses a blind camera shake deblurring method based on the L0 sparse prior, and belongs to the technical field of digital image processing. The blind camera shake deblurring method is a method for deblurring blurred images caused by camera shaking, and various space-unchanged camera shaking blurred kernels, namely the point spread functions, can be estimated. The blind camera shake deblurring method solves the problem that a current variational bayes estimation method is high in computing complexity and solves the problem that a current maximum posteriori estimation method lacks strict optimization theory supports. The blind camera shake deblurring method comprises the steps of firstly, introducing remarkable edge sparse prior based on the L0 norm, and using the iterative hard threshold compressed method to achieve recessive automatic prediction of remarkable edge characteristics, secondly, introducing camera shake blurred kernel sparse prior, and using the iterative repeated weighted least square method to achieve rapid estimation of the blurred kernels, and finally, using the image non-blind deblurring method based on super-Laplacian prior to obtain a high-quality deblurred image. The flow diagram of the blind camera shake deblurring method is shown in the figure 1.

Devices systems, and methods can characterize an optical surface of an object. A wavefront sensor system focuses light energy propagating from the object to form a pattern on a detector. The system maps the pattern to an array with a transform function such as a Fourier transform. The values of array correspond to characteristic locations and signals in a transform space, for example an intensity of spatial frequency signals in frequency space. The characteristic location and intensity of these signals in transform space are used to measure the optical surface. For example, a characteristic frequency of a spatial frequency intensity peak in Fourier transform space can be used to estimate the location of spots on the detector. Alternatively, the characteristics can be used to the measure sphere, cylinder and axis of a wavefront, wavefront elevation maps and point spread functions, often without locating positions of individual spots on the detector.

A restoration filter generation device that generates a restoration filter for a restoration process on the basis of a point spread in an optical system, the restoration process being performed on luminance system image data as image data concerning a luminance which is generated on the basis of image data for each color of plural colors acquired by an image pickup device having the optical system, the restoration filter generation device includes a first transfer function acquisition device, a correction information acquisition device, a second transfer function acquisition device, a third transfer function calculation device, and a restoration filter generation device that generates the restoration filter for the restoration process on the basis of the third transfer function calculated by the third transfer function calculation device.

The present invention relates to a super-resolution spectral imaging system and a super-resolution spectral imaging method based on a scattering medium. The super-resolution spectral imaging system comprises a calibration branch A, a scattering medium 4, a lens 5, a detector 6 and a branch B to be detected, wherein the calibration branch A comprises a light source module 1, a first collimation beam expansion system 2 and a pinhole 3, and the branch B to be detected comprises a light source 7 to be detected, a second collimation beam expansion system 8 and a target 9. According to the embodiments of the present invention, the point spread functions of the system are measured when the light source module outputs different wavelengths so as to construct the spectral point spread function (SPSF), the spectral reconstruction is achieved by using the compressed sensing (CS) method while the scattering medium with the appropriate scattering mean free path is matched, and the speckle receivedby the camera is subjected to convolution removing by using the point spread function corresponding to the wavelength of the light source to be detected, such that the maximum super-resolution imagingcan be achieved without the increase of the complexity of the system; and the super-resolution spectral imaging system has advantages of simple structure, easy control, low component cost, strong anti-disturbance capability and wide application field.

The invention relates to the space technology, and to the improvement of the star sensor calibration method. The invention uses the calibration system which including air cushion platform, single-star starlight simulator, star tracker, two-dimensional axial turntable platform and data-processing computer, its steps being: establishing point spread function model, establishing a centroid algorithm formula, establishing a centroid algorithm pixel frequency error model, and data acquisition. The invention provides a more practical point spread model; improving satellite sensor calibration precision; the calibration model is simple and easy to calculate.

The invention relates to a computer emulation system for actual ground object imaging by a space optical remote sensor. A target source matching module of the system is used for supplying ground object brightness and space information integrating data to a scanning module; a remote scanner emulation module is used for supplying remote sensor track parameters, posture parameters, optical system focal distances, point spread functions of all sub-fields of an optical system and physical parameters of an image sensor to the scanning module and a scanning information organization module; a clock unit of the emulation system is used for supplying time synchronization information to the scanning information organization module; the scanning module is used for receiving an image coordinate gray level time sequence of each image element according to the received information and supplying the image coordinate gray level time sequence to the scanning information organization module; and the scanning information organization module is used for obtaining a brightness matrix of a ground imaging emulation image according to the received information. According to the computer emulation system for the actual ground object imaging by the space optical remote sensor, provided by the invention, the ground imaging process can be emulated by the space optical remote sensor with any posture on any track; and the computer emulation system is compact in structure and is easy to update according to actual scientific research requirements.

Method for reducing computational time in inversion of geophysical data to infer a physical property model (91), especially advantageous in full wavefield inversion of seismic data. An approximate Hessian is pre-calculated by computing the product of the exact Hessian and a sampling vector composed of isolated point diffractors (82), and the approximate Hessian is stored in computer hard disk or memory (83). The approximate Hessian is then retrieved when needed (99) for computing its product with the gradient (93) of an objective function or other vector. Since the approximate Hessian is very sparse (diagonally dominant), its product with a vector may therefore be approximated very efficiently with good accuracy. Once the approximate Hessian is computed and stored, computing its product with a vector requires no simulator calls (wavefield propagations) at all. The pre-calculated approximate Hessian can also be reused in the subsequent steps whenever necessary.