Abstract: A method and apparatus for continuous presence conferencing is disclosed having voice-activated quadrant selection. A control processor in a multipoint control unit selects and assigns anchored sites to anchored regions of a composite video image. The control processor further selects a switched site according to a selection process and assigns the switched site to a switched region of the composite video image. The selection process for selecting the switched site includes evaluating audio signals received from the conference sites to determine a dominant audio signal and selecting the site associated with the dominant audio signal. A rotating site is selected and is assignable to any of the regions. A video processor processes the video signals according to the composite video image assignments to provide composite video signals for transmission to sites in the conference.

Abstract: In a method and apparatus for locating the acquisition target of a two-dimensional symbol in a pixel image, the image is convolved with a double template. The position with the greatest correlation coefficient between the double template and the image is selected as the location of the acquisition target. The double template comprises two identical parallel one-dimensional single templates corresponding to two lines that cross the symmetrical acquisition target at equal distances from the center of the acquisition target. Using a double template instead of only a single template reduces the possibility of finding false positive locations of the acquisition target. Since the double template comprises two identical halves, the image is preferably convolved with only one half of the double template and the double-template correlation coefficients are then generated from these intermediate single-template correlation results.

Abstract: A method and apparatus for characterizing the performance of either a printer used to print a two-dimensional symbol or an imaging system used to generate an gray-scale image of the printed symbol. After the image is generated, an acquisition target of the symbol is located. The fast Fourier transform of the gray-scale image is generated and certain hexagon-position quality measures are computed to characterize the quality of the acquisition target.

Abstract: A method and apparatus for characterizing the performance of either a printer used to print a two-dimensional symbol or an imaging system used to generate an gray-scale image of the printed symbol. After the image is generated, an acquisition target of the symbol is located. The quality of the acquisition target is characterized by thresholding the gray-scale image, run-length encoding the resulting binary image, and computing the correlation coefficient between the run-length-encoded image and a run-length-encoded representation of a defined acquisition target.