386 results about "Post filtering" patented technology

A user of a meta-search engine submits a query formulated with operators defining relationships between keywords. Information sources are selected for interrogation by the user or by the meta-search engine. If necessary, the query is translated for each selected source to adapt the operators of the query to a form accepted by that source. The query is submitted to each selected source and answers are retrieved from each source as a summary of each document found that satisfies the query. The answers are post-filtered from each source to determine if the answers satisfy the originally formulated query. Answers that satisfy the query are displayed as a list of selectable document summaries. The analysis includes computing a subsumption ratio of filtered answers to answers received that satisfy a translated query. The subsumption ratio is used to improve the accuracy of subsequent queries submitted by the user to the meta-search engine.

A post-filter includes a microphone array including at least two microphones to which a voice signal are input, a beam former which forms the voice signal input from the microphone array, a divider which divides a target sound containing noise input from the microphone array into at least two frequency bands at a predetermined frequency, a first filter which estimates the filter gain with the noise non-correlated between the microphones, a second filter which estimates a filter gain of one microphone of the microphone array or an average signal of the microphone array, an adder which adds the outputs from the first and second filters to each other, and a filter for reducing the noise based on the outputs from the adder and the beam former.

Multiple microphone noise suppression apparatus and methods are described herein. The apparatus and methods implement a variety of noise suppression techniques and apparatus that can be selectively applied to signals received using multiple microphones. The microphone signals received at each of the multiple microphones can be independently processed to cancel echo signal components that can be generated from a local audio source. The echo cancelled signals may be processed by some or all modules within a signal separator that operates to separate or otherwise isolate a speech signal from noise signals. The signal separator can include a pre-processing de-correlator followed by a blind source separator. The output of the blind source separator can be post filtered to provide post separation de-correlation. The separated speech and noise signals can be non-linearly processed for further noise reduction, and additional post processing can be implemented following the non-linear processing.

Adjacent blocks are identified in an image. Coding parameters for the adjacent blocks are identified. Deblock filtering between the identified adjacent blocks is skipped if the coding parameters for the identified adjacent blocks are similar and not skipped if the coding parameters for the identified adjacent blocks are substantially different.

An audio encoder, an audio decoder or an audio processor includes a filter for generating a filtered audio signal, the filter having a variable warping characteristic, the characteristic being controllable in response to a time-varying control signal, the control signal indicating a small or no warping characteristic or a comparatively high warping characteristic. Furthermore, a controller is connected for providing the time-varying control signal, which depends on the audio signal. The filtered audio signal can be introduced to an encoding processor having different encoding algorithms, one of which is a coding algorithm adapted to a specific signal pattern. Alternatively, the filter is a post-filter receiving a decoded audio signal.

An audio encoder, an audio decoder or an audio processor includes a filter (12) for generating a filtered audio signal, the filter having a variable warping characteristic, the characteristic being controllable in response to a time-varying control signal (16), the control signal indicating a small or no warping characteristic or a comparatively high warping characteristic. Furthermore, a controller (18) is connected for providing the time-varying control signal, which depends on the audio signal. The filtered audio signal can be introduced to an encoding processor (22) having different encoding algorithms, one of which is a coding algorithm adapted to a specific signal pattern. Alternatively, the filter is a post-filter receiving a decoded audio signal.

A microphone array system (16) for sound acquisition from multiple sound sources in a reception space surrounding a microphone array (18) that is interfaced with a beamformer module (28) is disclosed. The microphone array (18) includes microphone transducers (22) that are arranged relative to each other in N-fold rotationally symmetry, and the beamformer includes beamformer weights that are associated with one of a plurality of spatial reception sectors corresponding to the N-fold rotational symmetry of the microphone array (18). Microphone indexes of the microphone transducers (18) are arithmetically displaceable angularly about the vertical axis during a process cycle, so that a same set of beamformer weights is used selectively for calculating a beamformer output signal associated with any one of the spatial reception sectors. A sound source location module (30) is also disclosed that includes a modified steered power response sound source location method. A post filter module (32) for a microphone array system is also disclosed.

Systems, methods and apparatus are provided through which a specialized back-projection process reconstructs a finely detailed and crisp three-dimensional image (3-D ) from a series of two-dimensional (2-D) images by pre-filtering the 2-D images with a first group of settings before back-projecting the 2-D images into a 3-D image, and then post-filtering the 3-D image with another group of settings. In some embodiments, the first group of settings and the second group of settings are synergistically optimized in relation to each other to provide emphasis on a structure of interest in the object.

A digital sound system suitable for a digital speaker device for directly converting analog sound by a circuit using a ΔΣ modulator and a mismatch shaping filter circuit to output a plurality of digital signals and a plurality of speakers driven by the plurality of digital signals. A digital speaker driving device includes a ΔΣ modulator, a post filter, s driving circuits, and a power supply circuit to supply power to the ΔΣ modulator, the post filter and the s driving elements and the s driving circuits are adapted to s digital signal terminals.

An Ultraviolet-C (UVC) based portable water purification system employing a novel array of baffles increases the efficiency per unit energy of irradiating UVC light in the eradication of pathogens in the water. Closed loop feedback allows monitoring the application of UVC light power to ensure high levels of pathogen eradication. This system is capable of eradicating a wide range of waterborne bacteria, viruses, protozoa, helminthes, yeast, and mold found in natural freshwater sources worldwide. By adding pre- or post-filters, the system can remove harmful organic compounds, pesticides, inorganic compounds and heavy metals from the water. The system can also be used to eradicate pathogens in fluids other than water. As a feature of this invention, a communications systems that can reach geographically dispersed populations at low cost without the need to install costly wired communications infrastructure is combined with and powered by the water purification system. In one embodiment, a packet radio system is provided to create nodes in a wireless mesh communications system to provide voice, data, video and internet communications using an array of the water purifiers to create a wireless mesh network.

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.