514 results about "Aliasing" patented technology

An audio decoding apparatus decodes high frequency component signals using a band expander that generates multiple high frequency subband signals from low frequency subband signals divided into multiple subbands and transmitted high frequency encoded information. The apparatus is provided with an aliasing detector and an aliasing remover. The aliasing detector detects the degree of occurrence of aliasing components in the multiple high frequency subband signals generated by the band expander. The aliasing remover suppresses aliasing components in the high frequency subband signals by adjusting the gain used to generate the high frequency subband signals. Thus occurrence of aliasing can be suppressed and the resulting degradation in sound quality can be reduced, even when real-valued subband signals are used in order to reduce the number of operations.

The present invention relates to computer-based devices and methods supporting document exchange choreographies. More particularly, aspects of the present invention relate to devices and methods that facilitate evolution of systems by various combinations of choreography versioning, service versioning and document versioning. It provides for choreography management using a choreography agent and presents choreography-enabled interfaces to non choreography enabled applications. Additional aspects of the present invention include a graphical design tool and transparent aliasing of a host service as multiple context setting franchised services. Particular aspects of the present invention are described in the claims, specification and drawings.

Described herein is a method and sensor of processing time-of-flight (TOF) signals in a TOF camera system including an illumination unit and an imaging sensor. The method comprises illuminating the scene with light at a first frequency, detecting reflected light from at least one object in the scene at the first frequency, and determining a phase measurement using I and Q values. In addition, the scene is illuminated with light at a second frequency, the second frequency being 2⁻ⁿ of the first frequency where n=1, 2, . . . , etc., and the signs of I and Q values for both the first and second frequencies is used to determine the presence of aliasing in the phase measurement so that it can be corrected. The phase measurement is then corrected for aliasing and the effective range of the TOF camera system is extended by multiples of 2n. In addition, relative signal strength needs to be considered in accordance with the reflectivity of objects within the scene. For a reflectivity of 4% and no aliasing, the ability to detect an object decreases with distance (30). For an aliased phase measurement for an object with a reflectivity of 100%, the ability to detect the object is substantially constant (35).

An MRI image processing and analysis system may identify instances of structure in MRI flow data, e.g., coherency, derive contours and/or clinical markers based on the identified structures. The system may be remotely located from one or more MRI acquisition systems, and perform: perform error detection and/or correction on MRI data sets (e.g., phase error correction, phase aliasing, signal unwrapping, and/or on other artifacts); segmentation; visualization of flow (e.g., velocity, arterial versus venous flow, shunts) superimposed on anatomical structure, quantification; verification; and/or generation of patient specific 4-D flow protocols. An asynchronous command and imaging pipeline allows remote image processing and analysis in a timely and secure manner even with complicated or large 4-D flow MRI data sets.

A method of providing an aliased telephone number provided. A user may request an alternate telephone number to protect his privacy when making calls. When the user transmits a call, a service provider detects that the call should be linked with an aliased telephone number. The provider may then substitute the aliased number for the originating number such that the recipient sees the aliased number on a caller identification module. Likewise, where someone sends a call to an aliased number, the service provider may cross reference the aliased number with an actual telephone number and either augment data information associated with the call with the actual number, or replace the aliased number with the actual number. The aliased number may be time sensitive and may have an expiration date. The system and method allow users to obtain telephone numbers for time-limited events.

The invention discloses an electric system low-frequency oscillation detection method. On the basis of the existing nonlinear and non-stable signal empirical mode decomposition algorithm, the improved empirical mode screening algorithm enables the electric system low-frequency oscillation detection method to adapt to low-frequency oscillation signal processing, decomposed eigen mode components are combined with low-frequency oscillation mode physical expression meaning, and accordingly all low-frequency oscillation mode parameters of low-frequency oscillation sampling signals are recognized. The electric system low-frequency oscillation detection method reduces influence of the endpoint effect through improved mixed endpoint forecast, removes overshoot and undershoot by adopting triple B spline interpolation, simultaneously effectively reduces mode aliasing degree, analyzes and detects aliasing mode parameters through refined complex wavelets, controls algorithm screening depth through the improved energy elementary error screening stopping condition, reduces damping loss of mode components, and accordingly effectively improves low-frequency oscillation mode characteristic parameter detection accuracy.

A frequency-warped processing system using either sample-by-sample or block processing is provided. Such a system can be used, for example, in a hearing aid to increase the dynamic-range contrast in the speech spectrum, thus improving ease of listening and possibly speech intelligibility. The processing system is comprised of a cascade of all-pass filters that provide the frequency warping. The power spectrum is computed from the warped sequence and then compression gains are computed from the warped power spectrum for the auditory analysis bands. Spectral enhancement gains are also computed in the warped sequence allowing a net compression-plus-enhancement gain function to be produced. The speech segment is convolved with the enhancement filter in the warped time-domain to give the processed output signal. Processing artifacts are reduced since the frequency-warped system has no temporal aliasing.

The invention discloses a novel file-static-structure-attribute-based malware detection method, in particular a detection method for portable execute (PE) files and executable and linkable format (ELF) files. The method comprises the following steps of: in a training phase, extracting a file sample static structure attribute; preprocessing data, performing selection filtering by using a selectionfiltering algorithm and training a classifier by using the data; and in a detecting phase, classifying detected files by using the trained classifier according to the filtered static structure attribute to obtain a result indicating whether the files are malware or normal files. The novel file-static-structure-attribute-based malware detection method detects known or unknown malware with the accuracy of over 99 percent, has short detection time, occupies a few system resources and can be actually deployed in antivirus software. The method is not influenced by technology such as packing, aliasing, deformation, polymorphism and the like, can be applied to Windows and Linux platforms at present and also can be applied to embedded platforms such as various mobile phones, palm computers and the like.

Artificial bandwidth expansion devices, systems, methods and computer code products are disclosed for expanding a narrowband speech signal into an artificially expanded wideband speech signal. Embodiments of the invention can operate by forming an unshaped wideband signal based on the narrowband speech signal, such as through aliasing, and shaping the wideband signal into the artificially expanded wideband speech signal by amplifying/attenuating the unshaped wideband signal using a function generated by a neural network. Weights of the neural network can be set by a training/learning subsystem which generates genomes containing the neural network weights based on simulated environments in which a device employing the artificial bandwidth expansion is expected to operate.

The invention discloses a monitoring method for time reversal damage to no-datum Lamb wave of an engineering structure. The monitoring method comprises the following steps of: distributing a group of excitation/sensing arrays on a structure to be monitored; building detection channels, and collecting Lamb wave response signals of all excitation/sensing channels; intercepting the response signals, and then conducting time reversal to obtain time reversal structure response signals; loading the time reversal structure response signals onto corresponding excitation, and collecting time reversal focusing structure response signals on the corresponding sensing; and in the time reversal focusing structure response signals of all the detection channels, extracting the occurrence time difference of focusing main wave crest and sidelobe signals, taking the occurrence time difference as a characteristic parameter, calculating to obtain the position and approximate range of the damage by adopting an ellipse positioning method, and analyzing and judging the health condition of the structure to be detected. With the method, the wave packet extension and signal aliasing caused by frequency dispersion can be eliminated, no-datum active positioning and detection to the Lamb wave can be realized, and the healthy monitoring practicalization of the structure can be benefited.

The method for forming an image with a wide dynamic range makes use of an image sensor containing subsets of pixels that can be individually reset. After an initial reset (21), a pixel or row of pixels is exposed (22) for a first time interval and the gray value(s) (P_long⁽²⁵⁵⁾) are read out (23) and stored (24). The pixel or row of pixels is then reset (25) and exposed (26) for a second, shorter time interval. The second gray value(s) (P_short⁽²⁵⁵⁾) is/are read out (27) and either stored or immediately combined (28) with the first gray value(s) (P_long⁽²⁵⁵⁾) by means of a merging function (ƒ). The merging function (ƒ) ensures a monotonic, smooth change in output from the lowest to the highest gray values. The procedure is repeated for all pixels or rows of pixels in the image sensor, thus obviating the need for the storage of complete images. The method reduces temporal aliasing to a minimum and eliminates spatial aliasing.

The present invention relates to a magnetic resonance spectroscopic imaging (MRSI) method, specifically to a magnetic resonance spectroscopic imaging method with up to three spatial dimensions and one spectral dimension. Interleaving dynamically switched magnetic field gradients into the spectroscopic encoding scheme enables multi-region shimming in a single shot to compensate the spatially varying spectral line broadening resulting from local magnetic field gradients. The method also employs sparse spectral sampling with controlled spectral aliasing and nonlinear sampling density to maximize encoding speed, data sampling efficiency and sensitivity.

The invention discloses a double frequency laser grating interference two-dimensional measurement method and system with optical aliasing resistance, and belongs to a grating measurement technology. The system comprises a laser device, a grating interference mirror set and a photoelectric detection and signal processing unit. Two laser beams which are simultaneously output by the laser device, different in frequency and separated in space enter a polarizing beam splitter in parallel and in an incident mode. The first laser beam enters a reference grating in an incident mode after being reflected by the polarizing beam splitter to form multiple reference diffraction laser beams with multiple levels, the second laser beam enters a measurement grating in an incident mode after being transmitted by the polarizing beam splitter to form multiple measurement diffraction laser beams, three of the reference diffraction laser beams are sequentially and correspondingly joint with the 0 laser beam, the +1 laser beam and the -1 laser beam in the measurement diffraction laser beams respectively to form an optical beat frequency, and two-dimensional relative motion information of the measurement grating is acquired through photoelectric detection and signal processing. By the adoption of the method and system, optical frequency aliasing, polarization state aliasing and corresponding periodic non-linear errors caused by traditional incomplete polarizing beam splitting are eliminated, and combination properties of a photoetching machine ultra-precise workpiece table position measurement system can be improved when the double frequency laser grating interference two-dimensional measurement system is used for the photoetching machine ultra-precise workpiece table position measurement system.

The invention discloses a two-dimensional sub-pixel sampling-based super-resolution display method and a two-dimensional sub-pixel sampling-based super-resolution display device. Based on the characteristic of diversity of R, G and B primary color sub-pixel arrangement of flat panel display equipment, a Nyquist frequency limiting region of each primary color sub-pixel arrangement is calculated, and a group of R, G and B primary color anti-aliasing filters is designed on the basis of the calculated Nyquist frequency limiting region of each primary color sub-pixel arrangement, so that the aim of weakening and even eliminating the aliasing introduced by sub-pixel sampling is fulfilled while a high image sensing resolution is kept. According to the method and the device, corresponding anti-aliasing filtering is applied to R, G and B primary color components of an original image respectively, and then sub-pixel sampling is performed on the filtered image according to the spatial position structure of the two-dimensional sub-pixel arrangement of the display equipment. The visual perception resolution of the flat panel display equipment is improved at a lower cost on the premise of not changing any physical attribute, super-resolution display of the display equipment is realized, and meanwhile, the method is simple and easy to implement.

In order to process a subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, a weighter for weighting a subband signal by a weighting factor determined for the subband signal is provided to obtain a weighted subband signal. In addition, a correction term is calculated by a correction term determiner, the correction term determiner being implemented to calculate the correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the two weighting factors differing. The correction term is then combined with the weighted subband signal to obtain a corrected subband signal, resulting in reduced aliasing, even if subband signals are weighted to a different extent.

The invention provides a high-angular-resolution light filed obtaining device and an image generation method. The high-angular-resolution light filed obtaining device in which a light coding aperture is combined with a micro lens array is constructed to solve the problem that resolution tradeoff causes low spatial resolution or image aliasing leads to decrease of the quality of a light field image. The high-angular-resolution light filed obtaining device comprises a main lens, the coding aperture, the micro lens array and a sensor which are successively arranged along a light transmission path. On the premise that the positional resolution of the light field is not increased, depth information in light field data is used to improve the angular resolution of the light field. The high-angular-resolution light filed obtaining device has the advantages of being high in the angular resolution, high in the signal to noise ratio, high in the passing rate and capable of collecting light-field videos. The light-field image generation method using the compressed sensing theory has the advantages of being high in the angular resolution and capable of removing image aliasing.

The invention discloses a demosaicing method and device of an image sensor. The method includes the steps that 2*2 serves as shortest sampling cycles, an original RAW image obtained through the image sensor with four different filters exists in each shortest sampling cycle is taken as an output result formed after original color gamut images of four full breadths are added through a sampling function; the conversion relations between brightness, chrominance components and the original color gamuts corresponding to the four filters of the image sensor are defined, and each RAW image is taken as an output result generated after adding brightness and the chrominance components of the four full breadths through the sampling function; demosaicing computation is carried out on the brightness and the three chrominance components, and a brightness and chrominance signal of a current pixel position is restored from input RAW data; a corresponding original color gamut image signal is obtained by converting the brightness and chrominance signal of the current pixel position through matrix operation after demosaicing. The method and device can solve the problems that the resolution ratio of output images after demosaicing is low and bright color aliasing is severe.

The invention discloses a double frequency laser grating interference three-dimensional measurement method and system with optical aliasing resistance, and belongs to a grating measurement technology. The system comprises a laser device, a grating interference mirror set and a photoelectric detection and signal processing unit. Two laser beams which are simultaneously output by the laser device, different in frequency and separated in space enter a polarizing beam splitter in parallel and in an incident mode. The first laser beam enters a reference grating in an incident mode after being reflected by the polarizing beam splitter to form multiple reference diffraction laser beams with multiple levels, the second laser beam enters a measurement grating in an incident mode after being transmitted by the polarizing beam splitter to form multiple measurement diffraction laser beams, five of the reference diffraction laser beams are sequentially and correspondingly joint with the (0, 0) level laser beam, the (0, +1) level laser beam, the (0, -1) level laser beam, the (+1, 0) level laser beam and the (-1, 0) level laser beam in the measurement diffraction laser beams respectively to form an optical beat frequency, and three-dimensional relative motion information of the measurement grating is acquired through photoelectric detection and signal processing. By the adoption of the method and system, optical frequency aliasing, polarization state aliasing and corresponding periodic non-linear errors caused by traditional incomplete polarizing beam splitting are eliminated.

The invention discloses a method for realizing fourier transform profilometry by using a binary encoding strategy. A high-frequency sine structure light pattern is decomposed into a series of binary encoding patterns according to a bit plane; a binary pattern sequence is projected to a three-dimensional target by using a projection device; synchronous photographing is performed by using a photographing device; binaryzation treatment is performed on a photographed binary image; a high-frequency sine structure light image is synthesized according to correspondence of the bit plane and a gray level image; the synthesized sine structure light image is treated by using the fourier transform profilometry to obtain a truncated phase; the truncated phase is subjected to phase unwrapping to obtain an absolute phase; the three-dimensional coordinate of the surface of an object is calculated by using the absolute phase and system calibration parameters. The method can be used for measuring the three-dimensional surface shape of the object with diffuse reflection characteristic. According to the method, the problem of spectrum aliasing and background light interference existing in the conventional fourier transform profilometry can be effectively avoided; the method has higher measurement accuracy.

A method for computing a high resolution gray-tone image from a sequence of low-resolution images uses an L₁ norm minimization. In a preferred embodiment, the technique also uses a robust regularization based on a bilateral prior to deal with different data and noise models. This robust super-resolution technique uses the L₁ norm both for the regularization and the data fusion terms. Whereas the former is responsible for edge preservation, the latter seeks robustness with respect to motion error, blur, outliers, and other kinds of errors not explicitly modeled in the fused images. This computationally inexpensive method is resilient against errors in motion and blur estimation, resulting in images with sharp edges. The method also reduces the effects of aliasing, noise and compression artifacts. The method's performance is superior to other super-resolution methods and has fast convergence.