Abstract: The invention facilitates adaptive compression of multi-level images, such as captured digital images of a whiteboard, etc., encoding a bitstream comprising a color image component and a black-and-white image component. Either or both of a color and a black-and-white image can be output to a user based on user desires, receiving device capabilities, etc.

Abstract: An improved method and block transform for image or video encoding and decoding, wherein transformation and inverse transformation matrixes are defined such that computational complexity is significantly reduced when encoding and decoding. For example, in the two-dimensional inverse transformation of de-quantized transform coefficients into output pixel information during decoding, only four additions plus one shift operation are needed, per co-efficient transformation, all in sixteen-bit arithmetic. Transformations provide correct results because quantization during encoding and de-quantization (sixteen bit) during decoding, via the use of one of three tables selected based on each coefficient's position, have parameter values that already compensate for factors of other transformation multiplications, except for those of a power of two, (e.g., two or one-half), which are performed by a shift operation during the transformation and inverse transformation processes.

Abstract: An improved method and block transform for image or video encoding and decoding, wherein transformation and inverse transformation matrixes are defined such that computational complexity is significantly reduced when encoding and decoding. For example, in the two-dimensional inverse transformation of de-quantized transform coefficients into output pixel information during decoding, only four additions plus one shift operation are needed, per co-efficient transformation, all in sixteen-bit arithmetic. Transformations provide correct results because quantization during encoding and de-quantization (sixteen bit) during decoding, via the use of one of three tables selected based on each coefficient's position, have parameter values that already compensate for factors of other transformation multiplications, except for those of a power of two, (e.g., two or one-half), which are performed by a shift operation during the transformation and inverse transformation processes.

Abstract: An improved method and block transform for image or video encoding and decoding, wherein transformation and inverse transformation matrixes are defined such that computational complexity is significantly reduced when encoding and decoding. For example, in the two-dimensional inverse transformation of de-quantized transform coefficients into output pixel information during decoding, only four additions plus one shift operation are needed, per co-efficient transformation, all in sixteen-bit arithmetic. Transformations provide correct results because quantization during encoding and de-quantization (sixteen bit) during decoding, via the use of one of three tables selected based on each coefficient's position, have parameter values that already compensate for factors of other transformation multiplications, except for those of a power of two, (e.g., two or one-half), which are performed by a shift operation during the transformation and inverse transformation processes.

Abstract: An improved method and block transform for image or video encoding and decoding, wherein transformation and inverse transformation matrixes are defined such that computational complexity is significantly reduced when encoding and decoding. For example, in the two-dimensional inverse transformation of de-quantized transform coefficients into output pixel information during decoding, only four additions plus one shift operation are needed, per co-efficient transformation, all in sixteen-bit arithmetic. Transformations provide correct results because quantization during encoding and de-quantization (sixteen bit) during decoding, via the use of one of three tables selected based on each coefficient's position, have parameter values that already compensate for factors of other transformation multiplications, except for those of a power of two, (e.g., two or one-half), which are performed by a shift operation during the transformation and inverse transformation processes.

Abstract: A system and method facilitating acoustic echo cancellation convergence detection is provided. The invention includes an acoustic echo cancellation convergence detector having a center clipping component, a convergence calculator, a convergence filter and a convergence statistic component. The invention provides for the acoustic echo cancellation convergence detector to provide an output regarding convergence of an adaptive filter based, at least in part, upon a filtered convergence statistic. Optionally, the acoustic echo cancellation convergence detector can provide an output associated with convergence history.

Abstract: An “Interference Canceller” provides a computationally efficient real-time technique for removing stationary-tone interference from signals. Typical sources of stationary tone contamination of signals include noise from power wiring (i.e., 50/60 Hz or 400 Hz and their harmonics), frame or line frequencies from electronic devices, and noise from computer fans, hard disk drives, etc. In general, the Interference Canceller adaptively builds and updates a model of stationary tone interference in consecutive frames of an input signal. This adaptively updated model is then used to extrapolate and subtract noise from subsequent frames of the input signal to generate a “clean” output signal. This output signal exhibits significant attenuation of stationary tone interference without eliminating important portions of the underlying signal or distorting the underlying signal with artifacts such as musical noise or nonlinear distortions.

Abstract: Optimized color codecs and methods of compressing and decompressing color images using programmable color space parameters are provided. In accordance with one method of encoding a color image, input data comprising input image pixel data and color space parameters is provided. The input image pixel data is compressed based on the color space parameter data. The color space parameter data is then appended to the compressed image pixel data. In accordance with one method of decoding a compressed color image, compressed data is provided that comprises compressed image pixel data and color space parameters. The color space parameters are separated from the compressed image pixel data. The compressed image pixel data is then decompressed based on the color space parameters.

Abstract: An “Overcomplete Audio Coder” provides various techniques for overcomplete encoding audio signals using an MCLT-based predictive coder. Specifically, the Overcomplete Audio Coder uses unrestricted polar quantization of MCLT magnitude and phase coefficients. Further, quantized magnitude and phase coefficients are predicted based on properties of the audio signal and corresponding MCLT coefficients to reduce the bit rate overhead in encoding the audio signal. This prediction allows the Overcomplete Audio Coder to provide improved continuity of the magnitude of spectral components across encoded signal blocks, thereby reducing warbling artifacts. Coding rates achieved using these prediction techniques are comparable to that of encoding an orthogonal representation of an audio signal, such as with modulated lapped transform (MLT)-based coders.

Abstract: Systems and methods are disclosed that facilitate real-time information exchange in a multimedia conferencing environment. Data Client(s) facilitate data collaboration between users and are maintained separately from audio/video (AV) Clients that provide real-time communication functionality. Data Clients can be remotely located with respect to one another and with respect to a server. A remote user Stand-in Device can be provided that comprises a display to present a remote user to local users, a digital automatic pan/tilt/zoom camera to capture imagery in, for example, a conference room and provide real-time information to an AV Client in a remote office, and a microphone array that can similarly provide real-time audio information from the conference room to an AV Client in the remote office. The invention further facilitates file transfer and presentation broadcast between Data Clients in a single location or in a plurality of disparate locations.

Abstract: A “multi-resolution signal renderer” provides a computationally efficient process for generating reduced-resolution versions of a hierarchical transform coded digital signal from the encoded coefficients of that signal. The multi-resolution signal renderer begins by decoding the transform coded signal up to the highest hierarchical resolution not exceeding the desired signal resolution. The multi-resolution signal renderer then operates in one of two modes to generate reduced resolution signals. First, to generate signals at coded hierarchical resolution levels, DC coefficients of the transform coefficients are scaled, and then lowpass filtered to reduce aliasing in the signal.

Abstract: A quality level determining the extent to which each image file is compressed is automatically computed for each image file in a set to ensure that the total size of the compressed image files does not exceed a predefined limit. The compressed size of each image file is initially determined when compressed at a predefined minimum acceptable level and at a nominal level. The relative complexity of the image files is determined based upon their high frequency energy content. As a function of the image file complexity, and starting with the compressed sizes initially determined, the appropriate quality level is determined for compressing each of the image files in an iterative process that ensures the total size of the compressed image files does not exceed the predefined limit, while retaining acceptable quality. Thus, a set of image files can be compressed optimally to fit within a limited storage.

Abstract: Harmonic distortion residual echo suppression (HDRES) technique embodiments are presented which act to suppress the residual echo remaining after a near-end microphone signal has undergone AEC, including harmonic distortion in the signal that was caused by the speaker audio signal playback. In general, an AEC module is employed which suppresses some parts of the speaker audio signal found in a near-end microphone signal and generates an AEC output signal. A HDRES module then inputs the AEC output signal and the speaker audio signal, and suppresses at least a portion of a residual part of the speaker audio signal that was left unsuppressed by the AEC module. This includes at least a portion of the harmonic distortion exhibited in the AEC output signal.

Abstract: A method and system of lossless adaptive Golomb/Rice (G/R) encoding of integer data using a novel backward-adaptive technique having novel adaptation rules. The adaptive G/R encoder and decoder (codec) and method uses adaptation rules that adjust the G/R parameter after each codeword is generated. These adaptation rules include defining an adaptation value and adjusting the G/R parameter based on the adaptation value. If the adaptation value equals zero, then the G/R parameter is decreased by an integer constant. If the adaptation value equals one, then the G/R parameter is left unchanged. If the adaptation value is greater than one, then the G/R parameter is increased by the adaptation value. In addition, the adaptive G/R encoder and method include fractional adaptation, which defines a scaled G/R parameter in terms of the G/R parameter and updates and adapts the scaled G/R parameter to slow down the rate of adaptation.

Abstract: A quality level determining the extent to which each image file is compressed is automatically computed for each image file in a set to ensure that the total size of the compressed image files does not exceed a predefined limit. The compressed size of each image file is initially determined when compressed at a predefined minimum acceptable level and at a nominal level. The relative complexity of the image files is determined based upon their high frequency energy content. As a function of the image file complexity, and starting with the compressed sizes initially determined, the appropriate quality level is determined for compressing each of the image files in an iterative process that ensures the total size of the compressed image files does not exceed the predefined limit, while retaining acceptable quality. Thus, a set of image files can be compressed optimally to fit within a limited storage.

Abstract: A self-descriptive microphone array includes a microphone array memory, such as, for example a ROM, EEPROM, or other conventional memory, which contains a microphone array device description. This device description includes parametric information which defines operational characteristics and configuration of the microphone array. In further embodiments, the microphone array uses any of a variety of conventional wired or wireless computer interfaces, including serial, IEEE 1394, USB, Bluetooth™, etc., to connect to a computing device. Once connected, the microphone array provides its device description to the computing device. Sound processing software residing within the computing device is then automatically configured for optimally interacting with one or more analog or digital audio signals provided by the microphone array. In another embodiment, the microphone array performs integrated self calibration for automatically updating the device description.

Abstract: A system and method facilitating image retouching is provided. The invention includes an image retoucher having a boundary detector and an image extender. The invention provides for the image retoucher to extend care pixels of at least one of a foreground and a background near a detected spurious boundary by altering the binary mask used for compression of the foreground and/or the background.

Abstract: A gradient-corrected linear interpolation method and system for the demosaicing of color images. The method and system compute an interpolation using some a current technique (preferably a bilinear interpolation technique to reduce computational complexity), compute a correction term (such as a gradient of a desired color at a given pixel), and linearly combine the interpolation and the correction term to produce a corrected, high-quality interpolation of a missing color value at a pixel. The correction term may be a gradient correction term computed from the current color of the current pixel. This gradient is directly used to affect and correct the estimated color value produced by the prior art interpolation technique. The gradient-corrected linear interpolation method and system may also apply a gradient-correction gain to the gradient correction term. This gradient-correction gain affects the amount of gradient correction that is applied to the interpolation.

Abstract: An “Interference Canceller” provides a computationally efficient real-time technique for removing stationary-tone interference from signals. Typical sources of stationary tone contamination of signals include noise from power wiring (i.e., 50/60 Hz or 400 Hz and their harmonics), frame or line frequencies from electronic devices, and noise from computer fans, hard disk drives, etc. In general, the Interference Canceller adaptively builds and updates a model of stationary tone interference in consecutive frames of an input signal. This adaptively updated model is then used to extrapolate and subtract noise from subsequent frames of the input signal to generate a “clean” output signal. This output signal exhibits significant attenuation of stationary tone interference without eliminating important portions of the underlying signal or distorting the underlying signal with artifacts such as musical noise or nonlinear distortions.

Abstract: An adaptive interpolation technique with artifact reduction is described that technique generates digital images with full-color RGB (red, green, blue) information, from raw pictures (e.g., Bayer-mosaiced single-color images) created by single-CCD digital cameras. The technique employs an improved criterion for choosing the interpolation criterion, which takes into account an output interpolated value. It employs small changes to filter coefficients, for better results and accommodation of “correction attenuation”. In one embodiment, the technique further employs a “correction attenuation” step, which reduces “color sprinkling” artifacts for certain kinds of diagonal edges. The technique makes only a single pass over the image; all colors are interpolated during that pass, vice the multiple passes required by other better performing algorithms (in some cases over ten).