1749 results about "Spatial frequency" patented technology

Carrier Interferometry (CI) provides wideband transmission protocols with frequency-band selectivity to improve interference rejection, reduce multipath fading, and enable operation across non-continuous frequency bands. Direct-sequence protocols, such as DS-CDMA, are provided with CI to greatly improve performance and reduce transceiver complexity. CI introduces families of orthogonal polyphase codes that can be used for channel coding, spreading, and / or multiple access. Unlike conventional DS-CDMA, CI coding is not necessary for energy spreading because a set of CI carriers has an inherently wide aggregate bandwidth. Instead, CI codes are used for channelization, energy smoothing in the frequency domain, and interference suppression. CI-based ultra-wideband protocols are implemented via frequency-domain processing to reduce synchronization problems, transceiver complexity, and poor multipath performance of conventional ultra-wideband systems. CI allows wideband protocols to be implemented with space-frequency processing and other array-processing techniques to provide either or both diversity combining and sub-space processing. CI also enables spatial processing without antenna arrays. Even the bandwidth efficiency of multicarrier protocols is greatly enhanced with CI. CI-based wavelets avoid time and frequency resolution trade-offs associated with conventional wavelet processing. CI-based Fourier transforms eliminate all multiplications, which greatly simplifies multi-frequency processing. The quantum-wave principles of CI improve all types of baseband and radio processing.

A control system for automatically detecting moisture on the windshield of a vehicle. The automatic moisture detecting system includes an optical system for imaging a portion of the windshield on to an image array sensor, such as a CMOS active pixel sensor. The voltages of each of the pixels which represents the illumination level is converted to a corresponding gray scale value by an analog digital converter. The gray scale values corresponding to the image are stored in memory. The spatial frequency composition of the gray scale values are analyzed to determine the amount of rain present. In order to provide a control signal to control the operation of the windshield wipers of the vehicle as a function of the amount of moisture present. The system is also adapted to detect the level of fog both on the interior of the windshield as well as the exterior of the windshield. By providing a system for automatically detecting the presence of fog on the interior and exterior of the windshield, serious performance limitations of known automatic rain sensors are eliminated.

The invention relates to holographic head-up displays, to holographic optical sights, and also to 3D holographic image displays. We describe a holographic head-up display and a holographic optical sight, for displaying, in an eye box of the display / sight, a virtual image comprising one or more substantially two-dimensional images, the head-up display comprising: a laser light source; a spatial light modulator (SLM) to display a hologram of the two-dimensional images; illumination optics in an optical path between said laser light source and said SLM to illuminate said SLM; and imaging optics to image a plane of said SLM comprising said hologram into an SLM image plane in said eye box such that the lens of the eye of an observer of said head-up display performs a space-frequency transform of said hologram on said SLM to generate an image within said observer's eye corresponding to the two-dimensional images.

A variety of optical arrangements and methods of modifying or enhancing the optical characteristics and functionality of these optical arrangements are provided. The optical arrangements being specifically designed to operate with camera arrays that incorporate an imaging device that is formed of a plurality of imagers that each include a plurality of pixels. The plurality of imagers include a first imager having a first imaging characteristics and a second imager having a second imaging characteristics. The images generated by the plurality of imagers are processed to obtain an enhanced image compared to images captured by the imagers. In many optical arrangements the MTF characteristics of the optics allow for contrast at spatial frequencies that are at least as great as the desired resolution of the high resolution images synthesized by the array camera, and significantly greater than the Nyquist frequency of the pixel pitch of the pixels on the focal plane, which in some cases may be 1.5, 2 or 3 times the Nyquist frequency.

The invention discloses an array of pixels to be arranged in electronic color imaging devices, where the risk of aliasing is reduced by arranging the pixels in the array according to irregular patterns. The array is provided with a first, a second and a third set of pixels representing a first, a second and a third color respectively. The pixels in the first set of pixels and / or the pixels in the second set of pixels are arranged in at least a first spatial frequency, and the pixels in the third set of pixels are arranged in at least a second spatial frequency. In addition, one of said first or second set of pixels may be arranged in at least a third spatial frequency. None of said first, second and third spatial frequencies are harmonics of each other. The array may be implemented in one or several different matrixes of pixels.

A process for obtaining an object image of at least one object (40) is described, wherein at least two partial images of the object (40) are taken under differing object conditions which are formed on the object with spatial patterns, wherein a non-linear dependence of the light detectable from the object point on the object conditions given at the object point exists and the partial images contain different contributions of various space frequency components of the object structure, and the desired object image is determined from the partial images by reconstruction of the space frequency components. Optical systems for implementing this type of process are also described.

Reading disorders are diagnosed and remediated in a subject by respectively measuring and improving contrast sensitivity for motion discrimination of the subject. A background is displayed on a monitor with a contrast and a spatial frequency. A test window is superimposed over the background and includes a test pattern with a contrast and a spatial frequency. The contrasts and the spatial frequencies are within respective ranges which stimulate the visual cortical movement system of the subject. The test pattern is then moved within the test window. The subject provides a signal indicative of the direction the subject believes the test pattern moved. In response to this signal, the contrast of the test pattern, the spatial frequency of the background, or the spatial frequency of the test pattern is modified, either by increasing or decreasing its respective value. This process is then repeated a number of times, cycling through predetermined combinations of test patterns and backgrounds. Contrast sensitivity may be measured to determine whether a child is dyslexic. Repeated stimulation by the methods and apparatus of the invention improves contrast sensitivity, thereby remediating dyslexia and improving reading ability.

One or more reflectance modifying agent (RMA) such as a pigmented cosmetic agent is applied selectively and precisely with a controlled spray to human skin according to local skin reflectance or texture attributes. One embodiment uses digital control based on the analysis of a camera images. Another embodiment, utilizes a calibrated scanning device comprising a plurality of LEDs and photodiode sensors to correct reflectance readings to compensate for device distance and orientation relative to the skin. Ranges of desired RMA application parameters of high luminance RMA, selectively applied to middle spatial frequency features, at low opacity or application density are each be significantly different from conventional cosmetic practice. The ranges are complementary and the use of all three techniques in combination provides a surprisingly effective result which preserves natural beauty while applying a minimum amount of cosmetic agent.

An image signal is input from an image input unit and is divided into different spatial frequency bands by applying a discrete wavelet transform thereto using a discrete wavelet transformation unit. On the basis of values of spatial frequency components, a region-of-interest extracts a region of interest by obtaining a distribution of motion vectors in the input image. A quantization unit applies quantization processing to the extracted region of interest and different quantization processing to other regions, and an encoder encodes the quantized image signal. Alternatively, motion of an image contained in the input image may be detected and the region of interest may be obtained based upon motion of this image.

A circuit fabrication and lithography process utilizes a mask including dense repetitive structures of features that result in a wide array of fine densely populated features on the exposed substrate film. Following this, a trimming procedure is performed to remove any unwanted fine patterned features providing multiple trimmed patterns on the substrate. An optional final step adds additional features as well as the interconnect features thus forming a circuit pattern. In this manner, all fine features may be generated using the exact same density of intensity patterns, and therefore, maximum consistency between features is established without the need for optical proximity correction. The secondary exposures are substantially independent from the initial dense-feature exposure in that the exposure of one set of features and the subsequent exposure of another set of features result in separate independent resist or masking layer reactions, thus minimizing corner rounding, line end shortening and other related spatial frequency effects and unwanted exposure memory effects.

A method of compensating for spatial audio frequency characteristics that varies in accordance with a mounting condition of a down firing speaker of an audio / video (AV) apparatus includes calculating a listening distance between the AV apparatus and a listener, calculating a distance between a speaker mounted on the AV apparatus and a neighboring reflective surface, setting a spatial frequency compensation filter value and a speaker frequency characteristic compensation filter value based on the calculated distances, and compensating for frequency characteristics of an audio signal by combining the spatial frequency compensation filter value and the speaker frequency characteristic compensation filter value.

An electronic endoscope system includes a video scope having a solid-state image sensor for successively producing a frame of color image-pixel signals, and an image-signal processor for producing a color video signal based on the frame of color image-pixel signals. A calculation system calculates a difference value between a value of a central single-color image-pixel signal and an average of values of one selected from single-color image-pixel signals surrounding the central single-color image-pixel signal. A color-balance alteration system alters the value of the central single-color image-pixel signal based on the difference value calculated by the calculation system. A selection system performs the selection of the circumferential image-pixel signals such that the circumferential image-pixel signals to be selected are farther from the central image-pixel signal, as a spatial frequency of an endoscope image to be reproduced based on the color video signals is lower.

Disclosed are systems, methods, devices, and apparatus to interrogate a clothed individual with electromagnetic radiation to determine if a concealed weapon is being carried. This determination includes establishing data corresponding to an image of the individual and processing data sets corresponding to a number of spatial frequency representations of different image portions to evaluate if the concealed weapon is present.

A method of dynamic resonance imaging is provided. A magnetic resonance imaging excitation is applied. Data in 2 or 3 spatial frequency dimensions, and time is acquired, where an acquisition order in at least one spatial frequency dimension and the time dimension are in a pseudo-random order. The pseudo-random order and enforced sparsity constraints are used to reconstruct a time series of dynamic magnetic resonance images.

An input device having a plurality of low-visibility sensor electrodes and method for using the same are provided. In one embodiment, an input device includes a display device and a plurality of sensor electrodes disposed over the display device. The sensor electrodes are configured to sense objects in a sensing region of the input device. The sensor electrodes include a plurality of spaced apart conductive traces, each conductive trace having a diameter less than about 10 um. The conductive traces are disposed such that the conductive traces form a moiré pattern with the display device, wherein said moiré pattern comprises a spatial frequency greater than about 10 cycles per centimeter.

The invention relates to a video encoder (201) for encoding a video signal. The video encoder comprises a segmentation processor (207) which divides the picture into picture regions. Preferably, picture regions having a high degree of flatness or uniformity are determined in this way. A characteristics processor (209) determine a spatial frequency characteristic for each picture region, and a coding controller (211) selects an encoding block size, such as a prediction block size for motion estimation, in response to the spatial frequency characteristic. An encode processor (213) encodes the picture using the selected encoding block size. Specifically, increasing block sizes are selected for increasing degrees of uniformity or flatness indicated by the spatial frequency characteristic. Thereby, an increasing proportion of high frequency components and a consistent choice of encoding block sizes are maintained, and thus the coding artefacts from many encoders having variable prediction block sizes is reduced. The invention is particularly suitable for H.264 and similar encoders.

An improvement in a method for quantitative modulated imaging to perform depth sectioned reflectance or transmission imaging in a turbid medium, such as human or animal tissue is directed to the steps of encoding periodic pattern of illumination preferably with a fluorescent excitation wavelength when exposing a turbid medium to the periodic pattern to provide depth-resolved discrimination of structures within the turbid medium; and reconstructing a non-contact three dimensional image of the structure within a turbid medium. As a result, wide field imaging, separation of the average background optical properties from the heterogeneity components from a single image, separation of superficial features from deep features based on selection of spatial frequency of illumination, or qualitative and quantitative structure, function and composition information is extracted from spatially encoded data.

A method and an apparatus for noninvasively and quantitatively determining spatially resolved absorption and reduced scattering coefficients over a wide field-of-view of a food object, including fruit or produce, uses spatial-frequency-domain imaging (SFDI). A single modulated imaging platform is employed. It includes a broadband light source, a digital micromirror optically coupled to the light source to control a modulated light pattern directed onto the food object at a plurality of selected spatial frequencies, a multispectral camera for taking a spectral image of a reflected modulated light pattern from the food object, a spectrally variable filter optically coupled between the food object and the multispectral camera to select a discrete number of wavelengths for image capture, and a computer coupled to the digital micromirror, camera and variable filter to enable acquisition of the reflected modulated light pattern at the selected spatial frequencies.

The present invention provides a technique for performing one or more aspects of video coding such as quantization, intra prediction coding or inter prediction coding in dependence on a perceptual model taking into account human sensitivity to data in the video signal. The perceptual model may relate to spatial frequency, temporal frequency, contrast sensitivity, colour sensitivity, a structural metric, and / or one or more parameters affecting perception such as motion in the video, the distance of a recipient user from the screen, and the size, aspect ratio or resolution of the screen of the recipient terminal.

The objective of the present invention is providing a method for fabricating high quality diffractive waveplates and their arrays that exhibit high diffraction efficiency over large area, the method being capable of inexpensive large volume production. The method uses a polarization converter for converting the polarization of generally non-monochromatic and partially coherent input light beam into a pattern of periodic spatial modulation at the output of said polarization converter. A substrate carrying a photoalignment layer is exposed to said polarization modulation pattern and is coated subsequently with a liquid crystalline material. The high quality diffractive waveplates of the present invention are obtained when the exposure time of said photoalignment layer exceeds by generally an order of magnitude the time period that would be sufficient for producing homogeneous orientation of liquid crystalline materials brought in contact with said photoalignment layer. Compared to holographic techniques, the method is robust with respect to mechanical noises, ambient conditions, and allows inexpensive production via printing while also allowing to double the spatial frequency of optical axis modulation of diffractive waveplates.

A magnetic resonance imaging (MRI) system, comprising: a magnetics system comprising: a B0 magnet configured to provide a B0 field for the MRI system; gradient coils configured to provide gradient fields for the MRI system; and at least one RF coil configured to detect magnetic resonance (MR) signals; and a controller configured to: control the magnetics system to acquire MR spatial frequency data using non-Cartesian sampling; and generate an MR image from the acquired MR spatial frequency data using a neural network model comprising one or more neural network blocks including a first neural network block, wherein the first neural network block is configured to perform data consistency processing using a non-uniform Fourier transformation.

A method is disclosed for deghosting seismic data. The data include measurements of a vertical component of particle motion and pressure. The measurements are substantially collocated and made at a plurality of spaced apart positions. The method includes transforming the data into the spatial frequency domain, and separating upgoing and downgoing wavefield components of the transformed data. Water surface multiples may also be removed by decomposing the signals made at a plurality of seismic energy source locations into upgoing and downgoing wavefields.

A polarization camera includes a microlement polarizer that is situated in proximity to a focal plane array. The microlement polarizer is selectively scanned with respect to an optical image direct to the focal plane array, and an image processor stores a set of images associated with the scanning. Based on the stored images, a polarization image can be produced and displayed. A periodic microelement polarizer modulates the individual images of the set, and these images can be processed by filtering in the spatial frequency domain to isolate contributions associated with one or a combination of Stokes parameters. After filtering, Stokes parameter based images can be obtained by demodulating and inverse Fourier transforming the filtered frequency domain data.

A radar imaging system is provided that directly measures the spatial frequency components of a scene via digital-beam-forming techniques applied along the cross-track dimension. Separate transmit and receive antennas provide increased integration time for the receive function, thus improving the signal-to-noise ratio. A segmented receive antenna is employed and processed as a series of interferometers sensitive to spatial frequency components of the scene corresponding to the separation between pairs of antenna elements. Range gating is used in the along-track dimension to divide the return from an illuminated swath into multiple range bins that may be processed independently. The system provides an improved signal-to-noise ratio and lends significant flexibility to the image formation process, improving the quality of the radar imaging. An embodiment having multiple transmit antennas is also provided that enables the generation of three-dimensional stereoscopic radar images.

Scatter radiation in an x-ray imaging system including an x-ray source and an x-ray detector is separated by using amplitude modulation to translate the spatial frequency of a detected x-ray beam to a higher frequency and provide separation from low frequency scatter signal. The low frequency content of the detected x-ray beam is then obtained by demodulating the detected modulated signal.

An endoscope system consists mainly of: an endoscope having a solid-state imaging device and an objective optical system that converges an object image on said solid-state imaging device; and a signal processing unit that processes an image signal produced by the endoscope so as to produce a video signal. The objective optical system includes an optical phase modulation member. The optical phase modulation member exhibits a response of 0.2 or more derived from an optical transfer function relative to a spatial frequency on the solid-state imaging device determined based on the Nyquist theorem, that is, a Nyquist frequency, over a wider range of distances than a depth of field offered by an objective optical system not having the optical phase modulation member.

A method of noncontact imaging for performing qualitative and quantitative analysis of wounds includes the step of performing structured illumination of surface and subsurface tissue by both diffuse optical tomography and rapid, wide-field quantitative mapping of tissue optical properties within a single measurement platform. Structured illumination of a skin flap is performed to monitor a burn wound, a diabetic ulcer, a decubitis ulcer, a peripheral vascular disease, a skin graft, and / or tissue response to photomodulation. Quantitative imaging of optical properties is performed of superficial (0-5 mm depth) tissues in vivo. The step of quantitative imaging of optical properties of superficial (0-5 mm depth) tissues in vivo comprises pixel-by-pixel demodulating and diffusion-model fitting or model-based analysis of spatial frequency data to extract the local absorption and reduced scattering optical coefficients.