Abstract:
A microphone array system including an input unit to receive sound signals using a plurality of microphones; a frequency splitter splitting each sound signal received into a plurality of narrowband signals; an average spatial covariance matrix estimator using spatial smoothing to obtain a spatial covariance matrix for each frequency component of the sound signal, by which spatial covariance matrices for a plurality of virtual sub-arrays, which are configured in the plurality of microphones, are obtained with respect to each frequency component of the sound signal and an average spatial covariance matrix is calculated; a signal source location detector to detect an incidence angle of the sound signal according to the average spatial covariance matrix calculated; a signal distortion compensator to calculates a weight for each frequency component of the sound signal based on the incidence angle of the sound signal and multiply the calculated weight by each frequency component.
Abstract:
A method and apparatus to separate first and second mixture signals received from two sensors and transformed into the frequency domain in two or more source signals. The signal separation method includes: calculating a global signal absence probability for each frame and a local signal absence probability for each frequency band of a corresponding frame for at least one of the first and second mixture signals; estimating a spectrum vector for each frequency band in which a noise signal is eliminated using the global signal absence probability; determining a plurality of frequency bands including at least one of a noise signal and a source signal using the local signal absence probability, and generating a source label vector which consists of a plurality of frequency bands assigned to each source, using an attenuation parameter and a delay parameter generated for each of the determined frequency bands; and multiplying the spectrum vector estimated for each frequency band by the source label vector, and obtaining signals separated according to the source signals.
Abstract:
A microphone array, beam forming method and apparatus using the microphone array, and a method and apparatus for estimating an acoustic source direction using the microphone array are provided. The apparatus for forming constant directivity beams comprising: a microphone array, which is comprised of first through n-th microphone sub-arrays, wherein each of the microphone sub-arrays comprises: a first microphone placed at a predetermined location on a flat plate, which commonly belongs to each of the microphone sub-arrays; and second and third microphones placed at locations perpendicularly spaced by a predetermined segment from a straight line connecting the first microphone and the center of the flat plate, the predetermined segment being determined depending on a target frequency allotted to reach of the microphone sub-arrays, a beam formation unit receiving voice signals output from the first through n-th microphone sub-arrays and generating a beam for each of the first through n-th microphone sub-arrays; a filtering unit filtering the beams output from the beam formation unit; and an adding unit adding the filtered signals output from the filtering unit.
Abstract:
A method and apparatus for recognizing and searching for a face using 2nd-order independent component analysis (ICA) are provided. The method includes performing PCA on an input original image and generating a low-pass filtered image by removing high-frequency component from the original image, subtracting the low-pass filtered image from the original image and obtaining residual image having only frequency-components, and performing ICA on the residual image and generating feature information corresponding to the original image. While an original ICA subtracts independent components (i.e., independent basis components) from gray scale images, the proposed 2nd-order ICA is robust to illumination variation since it is applied to make the remaining images correspond to high pass frequency components.