Abstract: A face verification method and apparatus is disclosed. The face verification method includes selecting a current verification mode, from among plural verification modes, to be implemented for the verifying of the face, determining one or more recognizers, from among plural recognizers, based on the selected current verification mode, extracting feature information from information of the face using at least one of the determined one or more recognizers, and indicating whether a verification is successful based on the extracted feature information.

Abstract: Apparatus including circuitry configured to: acquire correlation signals by correlating a photodetected signal with respective phase-shifted reference signals, the correlation signals comprising quadrature correlation signals and in-phase correlation signals. The circuitry is configured in such a way that the mean time of acquisition of the quadrature correlation signals and the mean time of acquisition of the in-phase correlation signals are substantially equal.

Abstract: There is provided a display control apparatus that allows an operator to grasp a factor leading a face recognition result at a glance and to confirm or modify the face recognition result on the spot. The display control apparatus comprises a similarity acquirer that acquires a similarity between each pair of partial regions of face images by performing collation processing between the each pair of partial regions of the face images, and a display controller that controls to overlay, on the face images, at least one of a first region the similarity of which exceeds a threshold and a second region the similarity of which does not exceed the threshold, and display the overlaid face images. The display controller controls to overlay and display the first region and the second region in contrast with each other on the face images.

Abstract: There is provided a display control apparatus that allows an operator to grasp a factor leading a face recognition result at a glance and to confirm or modify the face recognition result on the spot. The display control apparatus comprises a similarity acquirer that acquires a similarity between each pair of partial regions of face images by performing collation processing between the each pair of partial regions of the face images, and a display controller that controls to overlay, on the face images, at least one of a first region the similarity of which exceeds a threshold and a second region the similarity of which does not exceed the threshold, and display the overlaid face images. The display controller controls to overlay and display the first region and the second region in contrast with each other on the face images.

Abstract: There is provided a display control apparatus that allows an operator to grasp a factor leading a face recognition result at a glance and to confirm or modify the face recognition result on the spot. The display control apparatus comprises a similarity acquirer that acquires a similarity between each pair of partial regions of face images by performing collation processing between the each pair of partial regions of the face images, and a display controller that controls to overlay, on the face images, at least one of a first region the similarity of which exceeds a threshold and a second region the similarity of which does not exceed the threshold, and display the overlaid face images. The display controller controls to overlay and display the first region and the second region in contrast with each other on the face images.

Abstract: A System, Computer program product, and computer-executable method of authenticating a user to a remote computing network, the System, Computer program product, and computer-executable including receiving a first portion of authentication data at a server, wherein the first portion of authentication data includes at least one feature of an image and analyzing the received first portion of authentication data by comparing the first portion of authentication data to a second portion of authentication data stored at the server.

Abstract: A processor-implemented method for capturing and reproducing spatial sound. The method includes: capturing a plurality of input signals using a plurality of sensors within a sound field; subjecting each input signal to a short-time Fourier transform to transform each signal into a transformed signal in the time-frequency domain; decomposing each of the transformed signals into a directional component and a diffuse component; optimizing beamformer weights using vector based amplitude panning to determine an optimal directivity pattern for the diffuse component of each transformed signal; constructing a set of diffuse sound channels using the diffuse components of the transformed signals and the optimized beamformer weights; constructing a set of directional sound channels using the directional components of the transformed signals; and reproducing the sound field by distributing the directional and diffuse sound channels to a plurality of output devices.

Abstract: The invention relates to an external cavity tunable laser. The laser comprises an extracavity collimating lens arranged outside a laser cavity, and a laser output mirror, a laser gain medium, an intracavity collimating lens, an active optical phase modulator and a tunable optical filter all arranged sequentially inside the laser cavity. The laser further comprises an active polarization rotator arranged behind the tunable optical filter, a polarization beam splitter arranged behind the active polarization rotator, a first etalon and a first total reflection mirror arranged in the direction vertical to the optic axis of a laser cavity output lens, a second etalon and a second total reflection mirror arranged in the direction of the optic axis of the laser cavity output lens, and a laser drive and control circuit.

Abstract: A recognition-by-parts authentication system for determining if a physical test target represented in test image(s) obtained using an imaging device matches a physical training target represented in training image(s). The system includes a multitude of adaptive and robust correlation filters. Each of the adaptive and robust correlation filters is configured to generate correlation-peak-strength and distance-from-origin data using a multitude of related images. Each of the multitude of related images representing a similar part of a larger image. The related images originate from the test image(s) and training image(s).

Abstract: A coherent integration section synthesizes an IF signal stored in a memory and a C/A code replica generated by a code generation section using a mixer to calculate a correlation value, and integrates the correlation value using an integration section. An integration count monitoring section counts the integration count of the integration section. When a saturation control section has detected saturation of integration of the correlation values, the integration count monitoring section causes the integration section to suspend integration when the integration count is equal to or less than a reference count, and allows the integration section to continue integration when the integration count has exceeded the reference count.

Abstract: An optical correlator includes an image production device and an image capture device disposed in a common plane. An optical device such as a lens or mirror provides a Fourier transform of image information from the image production device onto the image capture device. An advantage of embodiments of the invention is its small size.

Abstract: An output beam from a laser is directed into an acousto-optic cell. The laser beam includes repeated sequences of two or more pulses. The acousto-optic cell is sequentially driven by RF voltages at two or more frequencies. A portion of the laser output beam is diffracted by the acousto-optic cell at two or more different angles to the laser output beam. This provides two or more secondary beams. One of the secondary beams includes only the first pulses of the sequences; the other includes only the second pulses of the sequences. The duration of the pulses in the laser beam is controlled to control time-averaged power in the secondary beams.

Abstract: Provided is a correlation apparatus based on symmetry of a correlation coefficient that can reduce complexity of hardware by reducing the number of adders and multipliers. Accordingly, when values of a real number part and an imaginary number part are exchanged with respect to a middle point of a correlation coefficient sequence and divided into two parts of left and right by the middle point of the correlation coefficient sequence, the values of the real number part and the imaginary number part are even-symmetrical with respect to the middle point of the divided two parts. Therefore, the number of the adders required for forming the correlation apparatus is reduced by at least 20% and the number of the multipliers is reduced by at least 70% in comparison with the 62 adders and the 64 multipliers required for a conventional correlation apparatus.

Abstract: Imaging techniques. The focus of an imaging device is varied while acquiring an image of an object. The resulting blurred image is deconvolved to generate, in one embodiment, a two-dimensional projection image of three dimensions of the object.

Abstract: A communications apparatus and method use tapped delay lines as multiplexers and demultiplexers. In one embodiment, a receiver (100) uses a tapped delay line (110) as a demultiplexer to acquire a burst communication at very high data rates in the range of 2.5 to 80 Gbps with low preamble overhead. A sliding window correlator (114) continually samples the delay line (110) to determine when a PN encoded word is contained therein. The transmission frequency is pre-acquired before any data is present through the use of a ring oscillator frequency calibration loop (130) that is imbedded within the tapped delay line (110).

Abstract: A scanning laser microscope is provided which includes at least one laser light source for emitting laser light, a plurality of modulating sections for adjusting the laser light emitted from each laser light source, a storage section for storing delay time information on an input/output of each modulating section, and signal production section for producing a driving signal to drive at least one modulating section selected from the plurality of modulating sections based on the delay time information of the at least one selected modulating section. The delay time information includes information on a response time from a start of driving to development of a function of each modulating section.

Abstract: A method and apparatus for enhancing the receiving and information identification functions of multiple access communications systems by employing one or more optical processors configured as a bank of 1-D correlators. The present invention is particularly useful in a DS/SS CDMA communications system, resulting in a multiuser CDMA system that approaches carrier to noise performance (C/N) as opposed to being limited by multiple access interference (MAI). The correlators are arranged in parallel to detect and/or demodulate the received signal, in conjunction with one or more complex algorithms to perform near-optimum multiuser detection, perform multipath combining and/or perform carrier Doppler compensation.

Abstract: After one or both of a pair of images are obtained, an auto-correlation function for one of those images is generated to determine a smear amount and possibly a smear direction. The smear amount and direction are used to identify potential locations of a peak portion of the correlation function between the pair of images. The pair of images is then correlated only at offset positions corresponding to the one or more of the potential peak locations. In some embodiments, the pair of images is correlated according to a sparse set of image correlation function value points around the potential peak locations. In other embodiments, the pair of images is correlated at a dense set of correlation function value points around the potential peak locations. The correlation function values of these correlation function value points are then analyzed to determine the offset position of the true correlation function peak.

Abstract: An acousto-optic scanning system, which relies on two counter propagating acoustic waves with the same frequency modulation. This scheme completely suppresses the linear frequency chirp, and thus enables the generation of fast non-linear scans and non-constant linear scans. By changing the phase between the modulating signals, this scheme also provides fast longitudinal scans of the focal point.

Abstract: The present invention pertains to a polarization independent tunable acousto-optical filter and the corresponding method. The filter diffracts an input light beam into a first input light beam unaffected by acoustic waves and a second input light beam affected by acoustic waves. A polarization beam displacer/combiner is employed to separate the input light beam into two orthogonal beams. Several polarized rotators are used to rotate the polarization of light by 90 degrees. An acousto-optical device makes the polarization of light with a particular wavelength rotate by 90 degrees. The two beams are then properly combined to form orthogonal beams. The filtering method has nothing to do with the polarization of the incident light. The filter has such advantages as a high extinction ratio, a small volume and a lower cost.

Abstract: An optically implemented wide bandwidth correlation system (10) that employs a multi-mode imaging device (42) and a particular modulation format to provide both in-phase and quadrature phase correlation components in a single correlation process. The correlation system (10) includes an optical source (12) that generates a laser beam (14) that is split into a first beam path (18) and a second beam path (20). The first split beam and a first electrical signal are applied to a first modulator (22) in the first path (18) and the second split beam and the second electrical signal are applied to a second modulator (24) in the second path (20). The modulated beams are then applied to the optical imaging device (42) that causes the beams to interfere with each other within an optical cavity (48).

Abstract: A spread spectrum signal detection system comprising two spatially separated receivers, a correlator, such as a time integrating correlator employing acousto-optic cells, which is connected to the outputs from the two receivers to produce a signal representative of the cross correlation function of the two spread spectrum signals, a filter arranged to transmit only the central portion of the cross correlation function and a signal processor to produce the cross spectral density and thereby determine the presence of the spread spectrum signal. The direction of arrival of the spread spectrum signal can be determined by measurement of the angle of the phase slope of the cross spectral density. The acousto-optic cells can be Bragg cells.

Abstract: In order to increase the available signal processing bandwidth of an acousto-optic coherent channelizer, the optical beam spot-shaping and projection components of the channelizer are configured to project M reference beam spots upon each photodetector of the channelizer's photodetector array. The parameters of the reference Bragg cell, reference signal R(t), and Fourier optics components are such that they project M reference beam spots upon each photodetector of the channelizer's photodetector array, where M is the desired system bandwidth multiplication factor. No change to the configuration of the photodetector array or its associated post-detection signal processing electronics is required.

Abstract: A apparatus and method for coherently stretching or compressing signals of nterest, i.e. without loss of information. A first, or tapping, Bragg cell has an acoustic signal launched in it which is modulated onto a laser carrier. The signal of interest is launched into a second, or signal, Bragg cell, and is similarly modulated onto the carrier exiting the first Bragg cell. Upon demodulation, the resultant signal, is the convolution of the two acoustic signals in the respective Bragg cells, but whose duration is either stretched or compressed according to the relative velocity between the acoustic signals in the two Bragg cells, and by the magnification of optics between the two cells. If the signal in the first Bragg cell is of such a short duration that it is effectively an impulse, the resultant signal is a coherently stretched or compressed replica of the signal launched into the second Bragg cell, i.e. the signal of interest.

Abstract: An apparatus including a first light modulator for modulating a first light beam with a signal, a second light modulator for modulating a second light beam with a reference signal, first lens means, positioned in an optical path of the second light beam, for introducing into the second light beam horizontal magnification/demagnification which gradually varies with respect to a vertical direction, a beam combiner for combining the first and second light beams, and photodetecting means for detecting the combined light beam received from the beam combiner. The apparatus, thus constructed, is capable of processing the 50 to 100 billion operations per second required for true Doppler (time compression/expansion) processing of SONAR signals.

Abstract: The invention is a method that considerably improves the rapidity of collection and recognition of electrical signals that are mixed with other signals that impede direct access. The subject of the invention is a method for detection, recognition and use of significant trains of modulated signals on a carrier frequency. The apparatus which provides for the method utilizes a sole crystalline Bragg cell wherein two signal trains travel colinearly through the cell.

Abstract: An optical system of an optical neural network model for parallel data processing is disclosed. Taking advantage of the fact that an auto-correlation matrix is symmetric with respect to a main diagonal and the weights for modulating the values of diagonals of the auto-correlation matrix are equal to each other, the configuration of an optical modulation unit is simplified by a one-dimensional modulation array on the one hand, and both positive and negative weights are capable of being computed at the same time on the other hand. In particular, the optical system makes up a second-order neural network exhibiting invariant characteristics against the translation and scale.

Abstract: A degenerate four-wave mixing arrangement employs a photorefractive crystal as a real time holographic recording medium to record a hologram of the noisy optical signal. The signal passes through the crystal and is phase conjugated by a self pumped barium titanate phase conjugator, and the resulting phase conjugate beam reads out the hologram and multiplicative noise is substantially reduced in the optical output signal.

Abstract: A novel channelized, hybrid time- and space-integrating acousto-optic (AO) spectrum analyzer is described. The architecture consists of two acousto-optic cells in a crossed cell configuration. The first acousto-optic cell is a wide bandwidth device that performs space-integrating spectral analysis and channelizes signals according to carrier frequency. The second acousto-optic cell, in conjunction with a modulated source, performs time-integrating spectral analysis of the signal envelope using the chirp algorithm. One possible application of the processor is to determine the carrier frequency and pulse repetition frequency (PRF) of received radar signals.

Abstract: An acousto-optic apparatus is described that varies the time delay of electrical signals over a continuum of delays. In the preferred embodiment, a light source, which can be either coherent or incoherent, emits an optical beam that is focused into an acousto-optic cell. An input electrical signal is used to drive the acousto-optic cell which, in turn, modulates the focused optical beam. Portions of the input optical beam are modulated and diffracted at angles proportional to the frequencies and phases contained in the input electrical signal. By appropriately choosing the cone of angles at which the light is focused into the acousto-optic cell, the diffracted optical beam can be made to overlap with portions of the undiffracted, unmodulated optical beam. All of the light exiting the acousto-optic cell is then collected onto a device for detection. Optical photomixing of the diffracted beam and the undiffracted beam is performed in order to derive the input electrical signal with a time delay.

Abstract: Optical systems are disclosed which are capable of generating and rapidly changing time delays of electrical signals for true time delay beam formation and beam steering. The systems utilize an interferometer configuration. A first optical modulator and a Fourier transform lens define a Fourier transform plane in a first leg of the interferometer. In a second leg of the interferometer, a second optical modulator provides beam steering to a prism stack, which produces a set of plane reference waves having a range of orientations required to generate a desired range of time delays. Preferably the optical modulators are acousto optic Bragg cells. Alternatively, a holographic optic element could be used in place of the prism stack.

Abstract: An adaptive filter having a correlation weighting structue having a single Bragg cell, acting as a tapped delay line and having an input and an output, the Bragg cell intensity modulating a write laser beam for computing correlation values, and modulating a read laser field strength for multiplying the correlation values by delayed signal values. A photorefractive element is arranged such that substantial portions of diffracted and undiffracted light components from the single Bragg cell overlap within the photorefractive element. A write laser is intensity modulated by an error signal to produce an optical write signal that is received at the photorefractive element input and which writes correlation coefficients in the photorefractive element. A read laser produces a light signal, a portion of which is diffracted by the single Bragg cell, the portion of the light signal that is not diffracted by the single Bragg cell being partially diffracted by the photorefractive element.

Abstract: A light beam frequency comb generator uses an acousto-optic modulator to generate a plurality of light beams with frequencies which are uniformly separated and possess common noise and drift characteristics. A well collimated monochromatic input light beam is passed through this modulator to produce a set of both frequency shifted and unshifted optical beams. An optical system directs one or more frequency shifted beams along a path which is parallel to the path of the input light beam such that the frequency shifted beams are made incident on the modulator proximate to but separated from the point of incidence of the input light beam. After the beam is thus returned to and passed through the modulator repeatedly, a plurality of mutually parallel beams are generated which are frequency-shifted different numbers of times and possess common noise and drift characteristics.

Abstract: A one-dimensional or two-dimensional transmission mode spatial light modulator (SLM) includes one or more heterojunction acoustic charge transport (HACT) channels 18 with surrounding layers 16,20 vertically adjacent to a multiple quantum well (MQW) region 14, grown above a thick semiconductor substrate 10 thick enough to allow a surface acoustic wave (SAW) to propagate and transparent to the incident light 40. The SAW is injected by a transducer 24, charge is carried to and from the HACT channel 18 by electrodes 32,34,36, and light 40 is applied to a surface 44 perpendicular to the MQW region 14. Each charge packet 19 in the HACT channel 18 invokes an electric field 52 within the MQW region 14 which determines the optical absorption and index-of-refraction thereof, thereby determining the intensity and/or phase of each output light beam 45. Light modulation is achieved by modulating the amount of charge injected.

Abstract: A one-dimensional or two-dimensional transmission mode spatial light modulator (SLM) includes two different mediums, one medium being a semiconductor comprising one or more heterojunction acoustic charge transport (HACT) channels 28 with surrounding layers 26, 30 vertically adjacent to a multiple quantum well (MQW) region 22, and the other being a transparent piezoelectric insulating substrate 10 thick enough to allow a surface acoustic wave (SAW) 13 to propagate therein. The SAW 13 is launched in the substrate 10 by a transducer 12 and generates electric fields which propagate the charge along the HACT channel 28 in the semiconductor medium 18. Electrodes 32, 34, 36 carry charge to and from the HACT channel 28, and light 40 is applied to a surface 44 perpendicular to the MQW region 22.

Abstract: An acousto-optical classifier for classifying wide bandwidth signals such as high resolution radar returns of ships or very short pulse length signals of radar emitters. This is accomplished by generating the Fourier transform power spectrum with an acousto-optic cell oriented in the Bragg configuration and a low power coherent light source such as a laser. The power spectrum is detected to provide inputs to a digital classifier.

Abstract: An acousto-optic correlator for wideband signals. The invention is defined by and relates to device in which a laser beam is split into two paths of a Mach-Zehnder interferometer arrangement. A first Bragg cell of which, modulated with a signal Re{S.sub.1 (t)exp(jw.sub.o t)}, receives the first beam that is reflected off a first flat mirror. A second Bragg cell of which, modulated with a signal Re{S.sub.2 (t)exp(jw.sub.o t)}, receives a beam that is reflected off a second flat mirror. The undiffracted light from both of the modulators is blocked. The diffracted light emitted from the first and second Bragg cells passes through first and second imaging lenses respectively. The two diffracted light beams are then combined with an angular separation between beams. The combined beam is incident upon a square-law detector array which is at the image plane of the imaging lenses. Due to the square-law detection process, terms of low frequency biases and complex correlation on a spatial carrier develop.