Abstract: A technique for processing optical input signals to produce optical output signals using only a single hologram for a plurality of circularly shifted code words used to encode the input signals. A spatial light modulator coupled to the each of the optical input signals encodes a corresponding one of the input optical signals, and the optical signals are linear combined for further processing. A matched filter composed of the single hologram receives the linear combination, and a two-dimensional microlens arrangement coupled to the matched filter emits each of the optical output signals from a corresponding microlens in the arrangement. Switching is engendered by controlling each spatial light modulator to thereby direct each input signal to the desired one of the microlens in the arrangement.

Abstract: In the image processing apparatus a matrix selector selects a position matrix for determining the gradation direction. The gradation direction is the direction of a contrast of a gradation at a position of a target pixel and a dispersion matrix for determining a spatial frequency at the position of the target pixel. Further, a pixel interpolator divides the target pixel into still smaller pixels. A table selector selects a conversion table for determining a gradation level of the smaller pixels based on the gradation level of the target pixel, the position matrix and the dispersion matrix.

Abstract: A method is presented for marking high-quality digital images with a robust and invisible watermark. It requires the mark to survive and remain detectable and authenticatable through all image manipulations that in themselves do not damage the image beyond useability. These manipulations include JPEG “lossy” compression and, in the extreme, the printing and rescanning of the image. The watermark also has the property that it can detect if the essential contents of the image has changed. The first phase of the method comprises extracting a digest or number N from the image so that N only (or mostly) depends on the essential information content, such that the same number N can be obtained from a scan of a high quality print of the image, from the compressed form of the image, or in general, from the image after minor modifications (introduced inadvertently by processing, noise etc.). The second phase comprises the marking.

Abstract: A system and method for reading the information stored in holograms and other diffractive objects. The information is read by analyzing the diffraction pattern produced when a laser beam is focused onto a small spot on the object and scanned across the object.

Abstract: A illumination device sequentially projects a selective set of spatially encoded intensity light pulses toward a scene. The spatially encoded patterns are generated by an array of diffractive optical or holographic elements on a substrate that is rapidly translated in the path of the light beam. Alternatively, addressable micromirror arrays or similar technology are used to manipulate the beam wavefront. Reflected light is collected onto an individual photosensor or a very small set of high performance photodetectors. A data processor collects a complete set of signals associated with the encoded pattern set. The sampled signals are combined by a data processing unit in a prescribed manner to calculate range estimates and imaging features for elements in the scene. The invention may also be used to generate three dimensional reconstructions.

Abstract: Systems and methods are described for obtaining two-wavelength differential-phase holograms. A method includes determining a difference between a filtered analyzed recorded first spatially heterodyne hologram phase and a filtered analyzed recorded second spatially-heterodyned hologram phase.

Abstract: A medical image photographing system includes: an information management apparatus for readably holding photographing order information including a patient ID and radiographing conditions, and for sending the photographing order information; a control apparatus for obtaining the photographing order information from the information management apparatus through a communication network; and a portable terminal for displaying the photographing order information obtained from the control apparatus, obtaining the information out of the displayed photographing order information, obtaining a panel identification information, and storing into a memory the obtained panel identification information, wherein the portable terminal has an input unit for inputting various commands.

Abstract: A medical image photographing system comprising a control apparatus for corresponding a photographing order information related to medical photography and a medical image and managing them, and a portable terminal for obtaining the photographing order information from the control apparatus; wherein the control apparatus has a first communication unit for communicating with the portable terminal, and a first control unit for transmitting the photographing order information through the first communication unit to the portable terminal; and the portable terminal has a second communication unit for communicating with the control apparatus, a display unit for displaying a display information, and a second control unit for receiving the photographing order information from the control apparatus through the second communication unit, extracting the photographing order information corresponding to a predetermined extract condition from a received photographing order information, and displaying a extracted photographi

Abstract: A method for processing a sparsely populated color digital image having colored pixels to produce a fully populated and noise clean color image including noise cleaning the sparsely populated image to provide a noise clean sparsely populated color digital image; and interpolating the noise clean sparsely populated image for producing color pixels with appropriate values missing from the sparsely populated color digital image by interpolating the color values for missing pixels from neighboring color pixels.

Abstract: An arrangement for embedding a watermark in an information signal is disclosed. In order to make the embedded watermark more robust against hacking, a property of the watermark is randomized (11) which is irrelevant for the watermark detection. One example is randomizing (111) the magnitudes (abs) of the Fourier transformed watermark. Another example is randomly shifting the spatial or temporal position of the watermark with respect to the signal at a relatively low temporal frequency. The invention allows embedding (13) of spatially different watermarks without affecting the performance of a detector.

Abstract: The present invention includes a method and apparatus for simulating, for example on a desktop computer, a specific view of a hologram. A preferred embodiment of this invention suitably enables, in medical imaging, the manipulation of intensity transformations (windowing and leveling), regions (cropping) and views (axial, coronal and lateral) and the display of the resulting simulations in substantially real time. In accordance with one aspect of the present invention, an approximation of substantially accurate pixel intensities is achieved by collapsing three-dimensional data onto a two-dimensional view, without the need for constructing complex summations of fringe patterns, as is typically required when constructing a hologram. A power function is suitably applied to each voxel in the data set. The values for a particular x, y coordinate are then summed along the z axis, with the resultant sum value being stored in a sum buffer for all values of x and y.

Abstract: An authentication system using a correlator that correlates an input with a reference wherein at least one of the input and reference comprises a phase volume mask having structures, preferably points, that are each less than about six microns in size and can have an aspect ratio (AR) greater than 1:1 so as to produce a phase encoded random pattern having millions of combinations in a mask that is as small as one square millimeter. The random pattern can be convolved with a second pattern, such as a biometric pattern, to produce a phase convolved mask. The correlator preferably is a nonlinear joint transform correlator that can use “chirp” encoding to permit the input to be located in a different plane than the reference. The correlator optically Fourier transforms images of the reference and input that are thereafter nonlinearly transformed and inverse Fourier transformed by a processor to determine the presence or absence of a correlation spike indicative of authenticity.

Abstract: An apparatus for detecting a hidden image, which is formed in a first area of a hologram, is disclosed. The apparatus has a laser device for generating a laser beam and projecting the laser beam to the hologram, and a sensing device for sensing light that reflects from the hologram. When the laser beam is emitted to the hologram at a first incident angle, at least one diffractive beam is generated by diffraction of the laser beam. The sensing device is capable of outputting a responding signal according to the characteristics of the diffractive beam. Additionally, if the laser beam is emitted to the hologram at an incident angle, which is not equal to the first incident angle, the diffractive beam cannot be generated so that the sensing device does not output the responding signal.

Abstract: Fractional Fourier transform properties of lenses or other elements or optical environments are used to introduce one or more positive-definite optical transfer functions outside the Fourier plane so as to realize or closely approximate arbitrary non-positive-definite transfer functions. Designs can be straightforwardly obtained by methods of approximation. The invention provides for single and multiple channel controllable optical processors which may be used for image or other types of computation, including computation with complex-valued arithmetic, visual color, and wide-spectrum optical signals. The invention also provides for synthesis of Fractional Fourier transforms, extensions to non-Hermite basis functions, phase-shifting filter elements and non-quadratic graded-index materials (which do not naturally invoke the Fractional Fourier transform operation).

Abstract: A method for segmenting video data into foreground and background portions utilizes statistical modeling of the pixels. A statistical model of the background is built for each pixel, and each pixel in an incoming video frame is compared with the background statistical model for that pixel. Pixels are determined to be foreground or background based on the comparisons.

Abstract: A system and method for creating and displaying representations of holographic images comprises a display device, digital image data, a simulation module configured to create a representation of a holographic image and display the representation on the display device, and a processor configured to control the simulation module. The digital image data may include a sequence of images selected by a user by utilizing a selection module. An inspection module inspects the sequence of images for errors. An image sizing module manipulates the digital image data to conform to a size of a final stereogram, and a color module manipulates the digital image data to conform to a color of the final stereogram. A sequence repair module fills any gaps in the sequence of images. When the user determines that the representation is satisfactory, an image data formatter configures the digital image data to conform to requirements of a service provider.

Abstract: A system and method for reading the information stored in holograms and other diffractive objects. The information is read by analyzing the diffraction pattern produced when a laser beam is focused onto a small spot on the object and scanned across the object.

Abstract: An optical coherent processor or correlator for processing an input image produced by an imaging device illuminated by a coherent light source utilizes an optical key for preventing unauthorized use of the processor. The principle underlying processing apparatus and method according to the invention uses an optical lock in combination with an encoded software key superimposed on a filter image. The optical lock, which is preferably in hardware form, consists of a first optical mask implementing a locking mask function that is preferably complex (phase and/or amplitude), which first optical mask is included in the optical path of the processor. The mask is fixed during assembly of the processor or correlator and a unique pattern is encoded thereon. The software key consists of a pattern defined by a key mask function that is displayed preferably using a spatial light modulator as part of a second optical mask included on the processor optical path.

Abstract: Temporal processing for realtime human vision system behavioral modeling is added at the input of a spatial realtime human vision system behavioral modeling algorithm. The temporal processing includes a linear and a non-linear temporal filter in series in each of a reference channel and a test channel, the input to the reference channel being a reference image signal and the input to the test channel being a test image signal that is an impaired version of the reference image signal. The non-linear temporal filter emulates a process with neural attack and decay to compensate for a shift in peak sensitivity and for frequency doubling in a spatio-temporal sensitivity function. The linear temporal filter accounts for the remaining subtleties in the spatio-temporal sensitivity function.

Abstract: A system and method for reading the information stored in holograms and other diffractive objects. The information is read by analyzing the diffraction pattern produced when a laser beam is focused onto a small spot on the object and scanned across the object.

Abstract: A method and system for performing three-dimensional pattern recognition by use of digital holography is disclosed. The complex amplitude distribution generated by an object is recorded by phase-shifting interferometry. The digital hologram contains information about the objects shape, location, and orientation. This information allows one to perform multi-dimensional pattern-recognition methods with a high degree of discrimination and to measure three-dimensional orientation changes.

Abstract: A method for displaying computer generated holograms of a display object is performed by computing fringe patterns produced by light interference from the display object. The steps are summarized as follows: three-dimensional data of the display object are converted into computational data for fringe pattern generation; a sampling rule for sampling computational data is selected; computational data are sampled according to a selected sampling rule; wavefronts generated by light illumination are computed by assuming that each sampled position has a light source; fringe patterns generated by computed wavefronts and a reference beam are computed; fringe patterns are stored as hologram images; sampling and a wavefront generation are repeated for all data; and a series of hologram images thus generated are displayed successively.

Abstract: A smoothing circuit smoothes lookup tables generated by a color conversion table generator, using a filter function selected from a filter function storage circuit, and supplies smoothed lookup tables to a color processing circuit. Density data supplied from a calibration circuit are converted into halftone dot % data according to the smoothed lookup tables. The halftone dot % data are interpolated and then converted into LD control data, which are supplied to laser diodes.

Abstract: A digital electronic camera includes a holographic medium, an imaging array disposed at a focal plane for converting optical information to digital information; and an optical system configured to store the digital information onto the holographic medium. An optical system for retrieving images stored in the medium may be provided inside the camera or as a separate appliance.

Abstract: A device is provided which detects image patterns which may cause photosensitive attacks, based on the contrast intensity and values of frequency bands having a peak value. A frame image constituting video is image analyzed for contrast intensity and spatial frequency, in the contrast detector and the peak seeker respectively.

Abstract: A system and method for reading the information stored in holograms and other diffractive objects. The information is read by analyzing the diffraction pattern produced when a laser beam is focused onto a small spot on the object and scanned across the object.

Abstract: A method and apparatus for detecting a pattern within an image. Image data (22) is received which is representative of the image. Filter values (70) are determined which substantially optimizes a first predetermined criterion (68). The first predetermined criterion (68) is based upon image data (22). A correlation output (40) is determined which is indicative of the presence of the pattern within the image data (22). The correlation output (40) is based upon the determined filter values (70) and the image data (22) via a non-linear polynomial relationship (78).

Abstract: A scheme for producing computer generated holograms in which a motion vector of each object to be displayed is detected, objects are classified according to their motions, a hologram fringe pattern for each classified group of objects is calculated separately by image processing stored basic patterns, and a hologram to be displayed is produced, by synthesizing all separately calculated hologram fringe patterns. In another aspect, a gaze point of the observer is determined, and a hologram to be displayed is produced by using high resolution hologram fringe patterns for objects located at the gaze point and low resolution hologram fringe patterns for regions other than the gaze point.

Abstract: Pattern-recognition computing can be accomplished using wave-type or other types of energy. In pattern-recognition computing which uses a plurality of wave-type energy input patterns modulated with quantized information, energy from the patterns combines to produce interference-based dynamic images. Component parts of a dynamic image are separated and recombined to produce logic and other computing process outputs. To produce a coordinated set of optics for pattern-recognition computing, waveforms at pixel-sized image components of the dynamic image are chosen to become contributors to the combined output if they will contribute (or can be modified to contribute) in a positive manner to a combined output waveform that obeys the logic rules of the device being produced. Iterative changes in input pattern characteristics are used to optimize the coordinated optics. Pattern-recognition computing can also use special interference and frequency-multiplexed logic.

Abstract: A method for the numerical reconstruction of digital holograms which allows simultaneously amplitude and quantitative phase contrast imaging. The reconstruction method computes the propagation of the field that would be diffracted by the hologram during a standard hologram reconstruction. The method requires the adjustment of several reconstruction parameters for the definition of a digital replica of the reference wave. When the set-up used for the hologram creation produces phase aberrations, the method includes a digital method for the correction of the phase aberrations. The phase contrast image is quantitative, meaning that the reconstructed phase distribution can be used for quantitative measurements. The method can be used to reconstruct a set of holograms taken in different conditions. The method can be used to reconstruct several images from a single hologram taken with more than one reference waves and/or more than one object waves.

Abstract: A system and method for reading the information stored in holograms and other diffractive objects. The information is read by analyzing the diffraction pattern produced when a laser beam is focused onto a small spot on the object and scanned across the object.

Abstract: A method for improving the quality of holographic images by reducing local noise in a holographic memory system is disclosed. The method is characterized by: storing a white reference image and a black reference image in the memory system, storing a series of data images in the memory system, applying a simple model based on a point-to-point of linear interpolation to the series of data images, the white reference image and the black reference image to provide a series of corrected data images having reduced noise.

Abstract: A scheme for producing computer generated holograms in which a motion vector of each object to be displayed is detected, objects are classified according to their motions, a hologram fringe pattern for each classified group of objects is calculated separately by image processing stored basic patterns, and a hologram to be displayed is produced by synthesizing all separately calculated hologram fringe patterns. In another aspect, a gaze point of the observer is determined, and a hologram to be displayed is produced by using high resolution hologram fringe patterns for objects located at the gaze point and low resolution hologram fringe patterns for regions other than the gaze point.

Abstract: A system and method for capturing and processing audio and video images for optimized transmission over a lower bandwidth communications channel are disclosed. A digital processing system receives video and audio signals from a media source such that the video and audio signals are representative of captured images and sounds as a multimedia signal. An optical processing system is coupled to the digital processing system and performs signal processing algorithms on the multimedia signal. A transceiver transmits the multimedia signal over a lower bandwidth communications channel wherein the multimedia signal is optimized for transmission over the lower bandwidth communications channel by the signal processing algorithms performed by the optical processing system.

Abstract: Collation Fourier image data (FIG. 1D) FB generated by performing the two-dimensional discrete Fourier transform (DFT) for the image data (FIG. 1C) of a collation pattern is synthesized with registration Fourier image data (FIG. 1B) generated by performing the two-dimensional DFT for the image data of a registration pattern. After amplitude suppression processing is performed for the resultant data, two-dimensional DFT is performed. A correlation peak is extracted from a correlation component area which appears in the synthesized Fourier image data (FIG. 1E) for which the two-dimensional DFT has been performed. A predetermined area including this correlation peak is then masked (FIG. 1F). The two-dimensional DFT is performed for the masked synthesized Fourier image data, and amplitude restoration processing is performed for the data. The resultant data is re-synthesized with the registration Fourier image data FA, and the two-dimensional IDFT is performed for the synthesized data.

Abstract: An adaptive structure of a Wiener filter is used to deconvolve three-dimensional wide-field microscope images for the purposes of improving spatial resolution and removing out-of-focus light. The filter is a three-dimensional kernel representing a finite-impulse-response (FIR) structure requiring on the order of one thousand (1000) taps or more to achieve an acceptable mean-square-error. Converging to a solution is done in the spatial-domain and therefore does not experience many of the problems of frequency-domain solutions. Alternatively, a three-dimensional kernel representing an infinite-impulse-response (IIR) structure may be employed. An IIR structure typically requires fewer taps to achieve the same or better performance, resulting in higher resolution images with less noise and faster computations.

Abstract: A distance measuring device includes first and second cameras, first and second Fourier pattern data generating sections, a pattern processing section, and a distance measuring section. The two cameras are spaced apart from each other by a predetermined distance. The first Fourier pattern data generating section generates first two-dimensional Fourier pattern data by performing two-dimensional discrete Fourier transform for image data picked up by the first camera as first pattern data. The second Fourier pattern data generating section generates second Fourier two-dimensional pattern data by performing two-dimensional discrete Fourier transform for image data picked up by the second camera as second pattern data. The pattern processing section synthesizes the first and second Fourier two-dimensional pattern data, and performs either two-dimensional discrete Fourier transform or two-dimensional discrete inverse Fourier transform for the synthesized data.

Abstract: A hologram observation method capable of accurately estimating a three-dimensional wave source distribution even when a wave source is close to a hologram observation plane. The hologram observation is performed according to a two-frequency hologram observation method to reconstruct a hologram image. A three-dimensional wave source position is obtained from the reconstructed hologram image, a virtual unit wave source is disposed at the obtained wave source position and an observed wave is synthesized. A hologram image obtained from the synthesized observed wave is reconstructed, and a wave source intensity obtained from the measured hologram image is divided by a wave source intensity at the hologram image obtained from the synthesized observed wave, thereby obtaining a true complex amplitude of the wave source.

Abstract: A scheme for producing computer generated holograms in which a motion vector of each object to be displayed is detected, objects are classified according to their motions, a hologram fringe pattern for each classified group of objects is calculated separately by image processing stored basic patterns, and a hologram to be displayed is produced by synthesizing all separately calculated hologram fringe patterns. In another aspect, a gaze point of the observer is determined, and a hologram to be displayed is produced by using high resolution hologram fringe patterns for objects located at the gaze point and low resolution hologram fringe patterns for regions other than the gaze point.

Abstract: Analog image data a SEM are converted into digital data, and are processed by a spatial filtering processing, histogram processing, threshold value setting, three-valued image data processing, noise reduction and the like. Area of a pattern in the three-valued image data is calculated by a labelling and calculation processing, and a pattern is sequentially detected by comparing the area of the pattern with a reference area value. The comparison and detection of the same or similar patterns repeated in the SEM image are performed by using the area of the pattern, and are not performed by a shape of the pattern, thereby resulting a precise detection at high speed by using a microprocessor. Since it is possible to perform a pattern recognition from the area value even though the pattern does not have a characteristic, it is possible to precisely detect and recognize a pattern image in high speed.

Abstract: A pattern collation apparatus is designed to identify a registration pattern and a collation pattern as identical patterns or not even with a rotation offset between the registration pattern and the collation pattern. The image data of a registration fingerprint is rotated through m.multidot.a degrees, and two-dimensional discrete Fourier transform is performed for the resultant image data to obtain registration Fourier image data. The registration Fourier image data with m=-90 to +90 are filed as registration Fourier image data. In collation processing, registration Fourier image data are read out from the registration Fourier image data in units of patterns, and each registration Fourier image data is synthesized with the collation Fourier image data, thereby performing collation between the registration fingerprint and the collation fingerprint.

Abstract: An optical scanning holography system which requires only a two dimensional scan to record three dimensional information from a fluorescent specimen wherein the optical scanning holography is based on scanning the specimen with a Fresnel zone pattern and detecting and decoding the fluorescent light reflected from the specimen. The flourescent light reflected from the specimen contains three dimensional information about the specimen so that once the fluorescent light is detected and decoded a three dimensional image of the specimen can be obtained and displayed using only the two dimensional scan.

Abstract: The hologram card generates a hologram image in response to an illumination light beam. The hologram card comprises a substrate of a first plastic material having a first refractive index. The substrate has a contoured surface. The contoured surface is formed to include localized topological features constituting a diffractive optical element. The diffractive optical element is structured to generate a hologram image when illuminated by the illumination light beam. The hologram card also comprises a protective layer of a second plastic material having a second refractive index that differs from the first refractive index by less than 0.2. The protective layer covers the contoured surface of the substrate. The protective layer is chemically bonded to, and directly contacts, at least the topological features constituting the diffractive optical element.

Abstract: The present invention provides a method for producing double-card anti-counterfeit marks with interlock protection based on the technique which combines nuclear technology with computer-generated hologram (CGH) technology and inspecting apparatus for the mark. The invention relates to the technical field of optical information processing in physics. The technical feature of the invention is to insert potential images R,T and matched potential images R',T' in the anti-counterfeit identification marks and in the inspecting identification marks respectively by means of charged particle track image in sampling coincidence with CGH. When R coincides with R', a certain message of genuineness for an identification mark will be shown, and when T coincides with T', different specific information in thousands of ways appears to prove the genuineness of the protected objects.

Abstract: A method and apparatus for correlating outputs of a plurality of environmental sensor signals to determine a situation. The method includes the steps of dividing a coherent light beam across a diameter of the light beam into a plurality of information transmission zones and modulating a portion of the light beam within at least some of the information transmission zones with a corresponding number of signals of the plurality of environmental sensor signals. The method further includes the steps of deflecting the modulated light beams of the at least some information transmission zones within a holographic memory to provide at least some correlated outputs among the plurality of environmental sensor signals and determining the situation based upon the at least some correlated outputs of the holographic memory.

Abstract: The reconstruction region of a hologram reconstructed image is segmented. A fast Fourier transform (FFT) is carried out after multiplying the hologram measurement data V(R) by a weighting function. A fast Fourier transform (FFT) is carried out after multiplying the antenna sensitivity inverse matrix A.sup.-1 (R'.sub.a,b) for each segment by inverse propagation function r'.sub.a,b exp(j2.pi.r'.sub.a,b /.lambda.) to find B.sup.-1.sub.a,b (s, t), and then multiplying this by a weighting function. After the two FFT outputs are multiplied by each other, inverse fast Fourier transform (IFFT) is carried out. Compensation is performed for the weighting function and the output is made the segment reconstructed image. In addition, radio hologram observation is carried out at two scan surfaces, a horizontal polarization antenna and a vertical polarization antenna are placed at each scan surface, and the voltage vector distribution received by the antennas is stored.

Abstract: The present invention resides in a Fourier filter to detect defects on semiconductor wafers. The present invention relates to a Fourier filter to detect defects on semiconductor wafers which is less susceptible to having the filter output affected by vibrations and which avoids the physical contact from conventional damping.

Abstract: A method of and system for compensating for geometric distortion in a two-dimensional image finds fiducial marks in the image plane corresponding to fiducial marks in the object plane. The invention includes performing a matched filter search to locate corner fiducials from an object plane in the image plane. Locating the corner fiducials permits locating the remaining fiducials in the image plane. A centroid calculation makes the location of the fiducials in the image plane more precise and permits the generation of a solution matrix. The solution matrix and a trajectory engine map the pixels in the image plane to compensate for magnification, tilt, pin cushion, barrel, and other types of geometric distortions.

Abstract: A multiresolution method and apparatus for searching of a database of images where the search is performed on compressed images, without first decompressing them. The method searches the database of compressed images first at a low resolution to obtain the relative quality of a match between a search template and a candidate image. If the match is below a particular threshold, the search is terminated without committing any further computational resources to the search. Conversely, if the match is above a particular threshold, the method enhances the resolution of the candidate image and then performs another match. As long as the relative quality of the match is above the particular threshold, the resolution of the candidate image is successively enhanced, until a match determination is made at a full resolution of the candidate image.

Abstract: In a pattern processing apparatus, a registration data preparation unit performs two-dimensional discrete Fourier transform of image data of a registration pattern to prepare registration Fourier image data. A collation data preparation unit performs two-dimensional discrete Fourier transform of image data of a collation pattern to prepare collation Fourier image data. A data synthesizing unit synthesizes the registration Fourier image data with the collation Fourier image data, both of which consist of phase and amplitude information, to output first synthesized Fourier image data. An image processing unit performs Fourier transform of the first synthesized Fourier image data to output second synthesized Fourier image data representing intensities of correlation components.