Hewlett-packard Development Company, L.p.

Georgia Tech Research Corporation

Ronald W Schafer

Bowon Lee

Majid Fozunbal

Steven W McLaughlin

Ton Kalker

Russell Manning Mersereau

Faramarz Fekri

Mathieu Claude Hans

Gregory Gilbran Slabaugh

Thomas Anthony Baran

A method for time delay estimation performed by a physical computing system includes passing a first input signal obtained by a first sensor through a filter bank to form a first set of sub-band output signals, passing a second input signal obtained by a second sensor through the filter bank to form a second set of sub-band output signals, the second sensor placed a distance from the first sensor, computing cross-correlation data between the first set of sub-band output signals and the second set of sub-band output signals, and applying a time delay determination function to the cross-correlation to determine a time delay estimation.

Time delay estimation

Various embodiments of the present invention are directed to adaptive methods for reducing acoustic echoes in multichannel audio communication systems. Acoustic echo cancellation methods determine approximate impulse responses characterizing each echo path between loudspeakers and microphones within a room and improve performance based on previously determined impulse responses. In particular, the methods adapt to changes in the room by inferring approximate impulse responses that lie within a model of an impulse response space. Over time the method improves performance by evolving the model into a more accurate space from which to select subsequent approximate impulse responses.

Methods and systems for reducing acoustic echoes in multichannel communication systems by reducing the dimensionality of the space of impulse responses

Various embodiments of the present invention are directed to methods for dereverberation of audio generated in a room. In one aspect, a method for dereverberating reverberant digital signals comprises transforming a reverberant digital signal from the time domain into Fourier domain signals using a computing device, each Fourier domain signal corresponding to a subband. For each subband of the Fourier domain signal, the method computes autoregressive model coefficients of the reverberation with the current and previous magnitudes of the Fourier digital signal, and inverse filters the magnitude of the Fourier domain signal using the computing device, based on the autoregressive model coefficients and previous magnitudes of the Fourier digital signal. The method includes inverse transforming the Fourier domain signals with filtered magnitudes into an approximate dereverberated digital signal.

Methods and systems for blind dereverberation

The invention features an improved, photo hull based method of generating a three-dimensional representation of a visual scene based upon a set of multi-view reference images. In one aspect, a visual hull containing the visual scene is computed. Visibility of points on the computed visual hull with respect to each reference image is computed. Photo-consistency of points on the computed visual hull along rays back-projected from a desired view is computed based upon reference images having visibility of the points. A photo hull containing the visual scene is generated by stepping along each back-projected ray. The photo-consistent points visible in the desired view are colored using color information contained in reference images having visibility of the photo-consistent points.

Image-based photo hulls

A system and method for enabling efficient error correction and encryption using wavelet transforms over finite fields. The system and method utilizes the combination of a channel encoder and channel decoder to correct errors to source data after transmission over a physical channel or storage in a storage medium. The channel encoder mathematically generates a set of wavelet coefficients by performing a combination of filtering and/or processing of a received message vector. The wavelet coefficients are then utilized by the channel encoder to cause its filters to transform message data into transmission data. The channel decoder receives the transmitted source data in the form of a code word/channel error combination and performs filtering to render a syndrome, representative of the channel error. Analysis of the syndrome is performed to determine the actual error, which is utilized to derive the actual source data.

Growing community of inventors

Mountain View, CA, United States of America

Ronald W Schafer