185 results about "Reference noise" patented technology

A method for removing a stationary noise pattern from digital images uses an adaptive noise estimation algorithm to calculate a prediction of the fixed pattern noise and a confidence estimate for the prediction. In one embodiment, a predicted noise value is obtained from the captured image and a predicted image derived from spatial and temporal pixel value prediction techniques. The predicted noise value is used to update a fixed pattern noise estimate only when the confidence estimate for the predicted image is high. In another embodiment, the confidence estimate is used as a weight factor for blending the noise prediction into the noise estimate. In yet another embodiment, the adaptive noise estimation algorithm is applied to a prediction area in the image for calculating scaling parameters which scaling parameters are used to calculate a noise estimate for the entire image based on a reference noise image.

A new technique for identifying from images a camera, or other imaging device such as a scanner, is based on the device's reference noise pattern, a unique stochastic characteristic of all common digital imaging sensors, including CCD, CMOS (Foveon™ X3), and JFET. First, one determines from images the sensor's reference pattern noise, which uniquely identifies each sensor. To identify the sensor from a given image, the presence or absence of the reference pattern noise in the image under examination is established using a correlation detector or other means.

The invention relates to an evaluating system and method based on radio astronomical instrument device electromagnetic radiation. The evaluating system comprises a microwave switch, a receiving antenna, a reference noise source, a signal source and an emitting antenna, wherein two normally-open contacts are arranged at one end of the microwave switch, the other end of the microwave switch is connected to a spectrometer through a pre-amplifier, the spectrometer is connected with a computer, the receiving antenna is connected to one normally-open contact of the microwave switch, the standard noise source is connected to the other normally-open contact of the microwave switch, the signal source is connected to the computer through the network, and the emitting antenna is connected to the output end of the signal source through a radio frequency cable. According to the system and method, by means of the technical index and observation requirements of a radio astronomical observation system, radio astronomical instrument device radiated emission is tested and evaluated, the influence of radio astronomical instrument device radiated emission on a radio telescope is analyzed, so that reference is provided for compatibility design, shielding design and site radio management of the radio astronomical observation system, and the engineering significance is high.

A printed circuit board (PCB) uses arrays of chip capacitors over the entire surface of the PCB. The PCB includes an upper conductive surface routing signals to components of the PCB, a lower conductive surface, vias between the upper and lower surfaces, and a layer of patches disposed between the upper and lower surfaces to which the vias and chip capacitors are connected. The chip capacitors connect the vias to the upper conductive surface. The use of chip capacitors in a periodic lattice extends the frequency range for suppressing noise in power planes of isolated capacitors from several hundred MHz or less to 4 GHz. Combining the capacitors along with the buried patches extends the low frequency cutoff of high frequency reference noise suppression circuits to 50 MHz or less.

The present invention relates to a method for signal processing comprising the steps of providing a set of prototype spectral envelopes, providing a set of reference noise prototypes, wherein the reference noise prototypes are obtained from at least a sub-set of the provided set of prototype spectral envelopes, detecting a verbal utterance by at least one microphone to obtain a microphone signal, processing the microphone signal for noise reduction based on the provided reference noise prototypes to obtain an enhanced signal and encoding the enhanced signal based on the provided prototype spectral envelopes to obtain an encoded enhanced signal.

In the frequency domain, the method comprises the following steps:a) calculating a first noise reference by analyzing the spatial coherence of the signals picked up;b) calculating a second noise reference by analyzing the directions of incidence of the signals picked up;c) estimating a main direction of incidence of the signals picked up;d) selecting as a referent noise signal one or the other of the noise references as a function of the estimated main direction;e) combining the signals picked up into a noisy combined signal;f) calculating a probability that speech is absent in the noisy combined signal on the basis of the respective spectral energy levels of the noisy combined signal and of the referent noise signal; andg) selectively reducing the noise by applying variable gain that is specific to each frequency band and to each time frame.

Systems and methods of improved noise reduction include the steps of: receiving an audio signal from two or more acoustic sensors; applying a beamformer to employ a first noise cancellation algorithm; applying a noise reduction post-filter module to the audio signal including: estimating a current noise spectrum of the received audio signal after the application of the first noise cancellation algorithm, wherein the current noise spectrum is estimated using the audio signal received by the second acoustic sensor; determining a punished noise spectrum using the time-average level difference between the audio signal received by the first acoustic sensor and the current noise spectrum; determining a final noise estimate by subtracting the punished noise spectrum from the current noise spectrum; and applying a second noise reduction algorithm to the audio signal received by the first acoustic sensor using the final noise estimate; and outputting an audio stream with reduced background noise.

The invention relates to a cross-correlation-based nuclear magnetic resonance full wave signal noise filtering method. Based on characteristics that noise is irrelevant to the sinusoidal signals of Larmor frequency but FID amplitude attenuation sinusoidal signals are relevant to the sinusoidal signals of Larmor frequency, the method comprises steps of filtering noise via cross-correlation operation, then fitting envelope of related wave forms, reconstituting correlation wave forms without noise and at last extracting FID signals in nuclear magnetic resonance full wave data by use of the deconvolution algorithm. According to the invention, calculated amount of operation data is small; power frequency, noise of harmonic waves, random noise and peak noise can be simultaneously suppressed; signal to noise ratio of the nuclear magnetic resonance full wave data is remarkably increased, thereby facilitating application range and detection depth of a nuclear magnetic resonance water explorer; additional reference noise eliminating devices are not required, so cost is reduced; and ideal filtering effects of the full wave data which are acquired at a time can be achieved via cross correlation, so measuring time is saved.

The invention provides a voice noise reduction method and a voice collection device. According to the voice noise reduction method, frequency-domain transform and filtering are carried out through a filter assembly on a noise-cancelled voice signal formed through filtering and a reference noise signal formed through filtering, an original noise signal corresponding to the reference noise signal and a noise-containing voice signal corresponding to the noise-cancelled voice signal are output in a filtered manner, and a first crosstalk-resistant filter unit forming the reference noise signal and a second crosstalk-resistant filter unit forming the noise-cancelled voice signal update filter coefficients under control. The technical scheme has the following advantages: by employing only one pair of adaptive filters and using a post-filter to control the updating of the filter coefficients of the one pair of adaptive filters, the structure is simplified; and by adjusting the filter coefficient updating weights of the voice signal and the noise signal in a targeted manner, excellent crosstalk-resistant and noise reduction effects are achieved.

The invention discloses an active noise reduction system and a method. The active noise reduction system comprises a sound acquisition device, a motion signal acquisition device, a controller and a sound playing device, wherein the sound acquisition device is used for acquiring error noise signals in the environment; the motion signal acquisition device is used for acquiring motion signals at a specific position on a device generating primary noise signals and related to the primary noise signals; the controller is used for using a support vector machine to generate reference noise signals according to the motion signals, adjust the reference noise signals according to the error noise signals and then generate secondary noise signals; and the sound playing device is used for playing the secondary noise signals in the environment. The error noise signals are generated by overlapping the primary noise signals and the secondary noise signals. In the above active noise reduction system and the method, the support vector machine is used for predicting noise in the environment in real time. The generated reference noise signals have real-time performance and accuracy, and the noise reduction effects are improved significantly.

A micropower neural amplifier with adaptive power biasing for use in multi-electrode arrays is provided. The micropower neural amplifier includes a low noise gain stage. The low noise gain stage is implemented using an amplifier and pseudoresistor elements.

A new technique for identifying whether images are derived from a common imager, e.g., a camera, or other imaging device such as a scanner, based on the device's measured or inferred reference noise pattern, a unique stochastic characteristic of all common digital imaging sensors, including CCD, CMOS (Foveon™ X3), and JFET. The measured or inferred noise pattern of two images may be extracted and then cross correlated, with a high correlation being consistent with a common imager. Various preprocessing techniques may be used to improve tolerance to various types of image transform. It is also possible to perform the analysis without explicit separation of inferred image and inferred noise.

The invention discloses an active noise reduction method and system. The active noise reduction method comprises the steps of setting a plurality of microphones used for synchronously receiving sound signals and a loudspeaker used for generating reverse signals, wherein the plurality of microphones comprise a reference microphone, an optical microphone and an error microphone; respectively determining a sound signal transfer relation between the reference microphone and the optical microphone and a sound signal transfer relation between the error microphone and the optical microphone; acquiring reference noise signals and actual noise signals by using the sound signal transfer relations, and determining a noise filtering coefficient matrix of the reference microphone; controlling the loudspeaker to generate reverse signals which are identical in amplitude and opposite in direction to the reference noise signals according to the noise filtering coefficient matrix, and performing noise reduction on signals acquired by the error microphone. The invention further provides an automobile equipped with the active noise reduction system, influences imposed on user interaction by noise in the automobile can be eliminated, and the user interaction experience is improved.

Acquired video signals are forwarded to pre-processing block (103) for sampling, gain amplification and A / D conversion, and then forwarded to image buffer (104). Video signals in image buffer (104) are forwarded to noise estimation block (106). On the basis of taking conditions, video signals and a reference noise model, noise estimation block (106) works out the quantity of noise per ISO sensitivity, and per color signal. The calculated noise quantity is forwarded to noise reduction block (105). On the basis of the noise quantity estimated at the noise estimation block (106), the noise reduction block (105) applies noise reduction processing to video signals in image buffer (104), and video signals after noise reduction processing are forwarded to signal processing block (108).

The invention discloses a narrow-band interference suppression method and a narrow-band interference suppression device. The narrow-band interference suppression device comprises a frequency determining unit, a self-adaptive filtering unit, and an interference eliminating unit, wherein the frequency determining unit determines the frequency position of the narrow-band interference in a receiving signal, forms a local oscillator signal which only comprises narrow-band interference frequency information, and provides the local oscillator signal serving as a reference noise source for the self-adaptive filtering unit; the self-adaptive filtering unit converts the reference noise source into an analog interference signal which is consistent with the narrow-band interference, and provides the analog interference signal which is consistent with the narrow-band interference for the interference eliminating unit; and the interference eliminating unit eliminates the analog interference signal which is consistent with the narrow-band interference from the receiving signal, and outputs a useful signal. The narrow-band interference suppression method and the narrow-band interference suppression device perform point-to-point sampling processing on the data, and have high response speed. During eliminating the narrow-band interference, the damage to the useful signal at the same frequency position is reduced.

The present invention relates to an audio processing system and method for automatically adjusting volume. The method includes steps of: calculating a noise level as a reference noise level; periodically calculating a new noise level of a predetermined time period, and dividing the reference noise level by the new noise level to obtain a ratio; sampling digital audio signals generated by a decoding unit to obtain a plurality of amplitude values, periodically calculating an audio energy value of the predetermined time period; multiplying the audio energy value by the ratio to obtain a reference audio energy value; calculating a gain value according to the reference audio energy value and the default gain value; updating the default gain value with the gain value; and signaling the gain amplifier to amplify the analog audio signals received with the gain value, thereby protecting users' hearing.

This invention provides a method for determining, in a speech dialogue system issuing speech prompts, a score value as an indicator for the presence of a wanted signal component in an input signal stemming from a microphone, comprising the steps of: using a first likelihood function to determine a first likelihood value for the presence of the wanted signal component in the input signal, using a second likelihood function to determine a second likelihood value for the presence of a noise signal component in the input signal, and determining a score value based on the first and the second likelihood values, wherein the first likelihood function is based on a predetermined reference wanted signal, and the second likelihood function is based on a predetermined reference noise signal.

A music piece reproducing apparatus has: a sound collecting unit collecting noise data of an ambient environment; an analyzing unit performing a frequency analysis to the noise data collected by the sound collecting unit and extracting a feature amount showing a feature of the noise data; a noise parameter database classifying the noise data every environment; and a reproducing unit reproducing music piece data which has been recorded in a recording medium and classified every category, wherein the analyzing unit classifies the noise data with reference to the noise parameter database on the basis of the extracted feature amount of the noise data, selects the previously-corresponded category of music pieces in accordance with a classification result of the noise data, and selects predetermined music piece data from music piece data classified into the selected category.

An apparatus and method for allocating a data rate in a multi-antenna system are provided, wherein a noise threshold corresponding to a modulation scheme, a coding rate, or a combination of both applied to a base layer from among a plurality of layers is set as a reference noise threshold, and a data rate is allocated to an enhanced layer among the plurality of layers, based on the reference noise threshold and a use or non-use of hierarchical transmission.

The invention discloses an automobile active noise reduction system and method. The automobile active noise reduction method comprises error microphones, a rotating speed acquisition device and a noise reduction controller. The error microphones are connected with the noise reduction controller and are used for collecting noise signals and outputting the noise signals to the noise reduction controller. The rotate speed acquisition device and the noise reduction controller are used for acquiring rotating speed signals of an engine and outputting the rotating speed signals to the noise reductioncontroller. The noise reduction controller is used for performing active noise reduction simulation according to the noise signals, the rotating speed signals of the engine, reference noise data of acorresponding vehicle type and an established transfer function, optimal control parameters are determined, and active noise reduction is performed based on the optimal control parameters. The automobile active noise reduction system and method can control the order noise of the engine, and can freely adjust a control area in a vehicle according to the number and position of installed error microphones. The automobile active noise reduction system and method can be conveniently and quickly additionally installed into the vehicle needing active noise reduction, the cost is low, the operation is simple, and drivers and passengers can obtain better driving experience.

Various systems and methods for clock management. As one example, a system for clock management is disclosed that includes a controllable oscillator, an oscillation control source, and a sample and hold circuit. The sample and hold circuit is disposed between the oscillation control source and the controllable oscillator, and is operable to introduce a transfer function having a sin x / x characteristic with a null at a switch frequency applied to the sample and hold circuit.

The invention discloses a non-contact heart rate measurement method based on a face video image. The method comprises the following steps: acquiring multiple frames of RGB images; searching a face area of the single-frame RGB image and determining a cheek center area as an interested face area ROI1, and performing space pixel averaging on a green channel of the ROI1 to obtain an average value s1i;extracting a part of fixed background area of the single-frame RGB image as an interested background area ROI2, and performing space pixel averaging on a green channel of the ROI2 to obtain an average value s2i; integrating the plurality of s1i to obtain an effective signal flow s1, and integrating the plurality of s2i to obtain a reference noise signal flow s2; performing normalization processing on the effective signal flow s1 and the reference noise signal flow s2, and then performing noise reduction to obtain a reconstructed signal flow sign; and calculating a heart rate value according to the reconstructed signal flow sign. According to the invention, the problems of low face motion and signal-to-noise ratio and the like in heart rate monitoring based on the face video image can be effectively solved.

System and method for improving a digital PLL's performance by making fine grained adjustments to the loop gain. A preferred embodiment comprises a plurality of loop gain adjustors (such as loop gain adjustors 605, 606, 607, and 608) that can incrementally adjust the loop gain. The incrementally adjusted loop gains are sequentially brought on-line so that the loop gain of the digital PLL is slowly decreased. By slowly decreasing the loop gain, the digital PLL is less perturbed by smaller noise transients that would take time to settle. Hence, the digital PLL can quickly acquire a signal and then decrease its loop gain and hence its bandwidth when it only needs to track a signal. The reduced bandwidth also reduces the overall noise in the digital PLL that is due to the reference noise contribution.

The invention discloses an active noise control method and system based on a fuzzy neural network and an armored vehicle driver's helmet. The method includes collecting a reference noise signal in a reference area by a reference microphone, and outputting it to a fuzzy controller as a reference signal; the error microphone collects noise The residual noise signal in the control area is used as an error signal, and is output to a fuzzy controller; and the fuzzy controller is based on an adaptive FX-RBF network training algorithm of a fuzzy neural network, and analyzes the reference signal and the error signal , and output the anti-phase target sound signal to the speaker. The active noise control based on the fuzzy neural network of the present invention has obvious noise reduction effect on noise below 2000 Hz, and the noise reduction effect on low frequency noise below 1000 Hz is particularly significant.

A new technique for identifying from images a camera, or other imaging device such as a scanner, is based on the device's reference noise pattern, a unique stochastic characteristic of all common digital imaging sensors, including CCD, CMOS (Foveon™ X3), and JFET. First, one determines from images the sensor's reference pattern noise, which uniquely identifies each sensor. To identify the sensor from a given image, the presence or absence of the reference pattern noise in the image under examination is established using a correlation detector or other means.

The invention discloses an earphone adaptive active noise control system and method. The system at least comprises a reference microphone which is used for collecting reference noise signals; an errormicrophone which is used for collecting error noise signals, wherein the reference microphone is set out of an earphone, and the error microphone is set in the earphone; a loudspeaker unit which is used for playing secondary sound signals; two analog-to-digital converters Ads which are respectively used for converting the reference noise signals and the error noise signals into corresponding digital signals; a digital-to-analog converter DA which is used for converting filtered output signals into analog signals and feeding back the analog signals to a secondary loudspeaker; and a processor which is used for updating a filtering coefficient and generating input signals of the secondary loudspeaker. According to the method, the problem that a common adaptive algorithm is insufficient in real-time tracking capability and excessive in computing delay is solved. The method has relatively good adaptivity to different environments and different earphone wearing modes. The earphone adaptiveactive noise control convergence performance and tracking performance are improved.

A traffic measurement device comprises a noise power setting unit configured to set a reference noise power, which is a reference value used to measure a traffic volume at a base station, a noise power measurement unit configured to measure a noise power at the base station, and a calculation unit configured to calculate the traffic volume based on the reference noise power and the measured noise power. Another traffic measurement device comprises a transmission power setting unit configured to set a reference transmission power, which is a reference value used to measure the traffic volume at a base station, a transmission power measurement unit configured to measure a transmission power at the base station, and a calculation unit configured to calculate the traffic volume based on the reference transmission power and the measured transmission power.

The invention relates to a system and a method for reducing background noise in magnetoencephalogram detection. A magnetic sensor array layer is arranged at the outer side of a head-mounted flexible substrate; a brain magnetic field sensor array and an outer magnetic field sensor array are distributed on left and right hemispheres of the brain; a magnetic shielding layer is arranged outside the magnetic sensor array layer; and a neck ring of a wearable magnetic field sensor is arranged on the neck of a human body. reduction of the background noise in magnetoencephalogram detection is achieved by collecting and analyzing a brain magnetic field of the head and an outer magnetic field of the head, analyzing the brain magnetic field of the neck and the outer magnetic field of the neck, fusing brain magnetic field information, carrying out noise analysis on the outer magnetic field information, obtaining a reference noise background signal, fusing the brain magnetic field information and subtracting the reference noise background signal, and a magnetoencephalogram with a high signal-noise ratio is obtained. The system and the method have the characteristics of being simple, convenient to implement, high in sensitivity, low in implementation cost, high in reliability, small in space and high in flexibility.