Abstract: Digital video contrast enhancement and skin tone correction by conversion to CIECAM02 color space with lightness transformation and a skin tone probability density function of hue and saturation.

Abstract: Base band compensation for an IF stage in a television provides significant advantages over compensation applied to the composite signal. Each base band color difference signal is filtered to obtain cross-talk elements, which are then applied to the opposite channel to eliminate the cross-talk components from the color difference signal channels. The compensation technique is applicable to IF stages generally, including those based on SAW filters. High and low gain compensation of the cross-talk compensated signals may also be performed to reduce distortion in the compensated signals. The base band compensation tends to reduce or eliminate visual artifacts in a television image, especially where sharp contrast transitions occur in the image.

Abstract: A system to reduce noise includes a noise measurement device that provides a measure of noise associated with a digital input video signal. A noise reduction filter provides a noise-reduced digital output video signal corresponding to the luma and chroma of the digital input video signal. The noise reduction filter has a parameter that varies on a pixel basis for the component of the digital input video signal as a function of the measure of noise. The range and sensitivity of the noise reduction can be user programmable.

Abstract: System and method for an all-digital audio receiver for a BTSC MTS audio signal or other composite signal that is FM modulated. A preferred embodiment comprises a digital FM demodulator for receiving an analog to digital quantized SIF signal and performing demodulation and outputting a composite audio signal, and a digital audio processor for decomposing the composite audio signal into at least the SAP, stereo and monaural signals for audio reproduction. In a preferred embodiment, the digital audio processor is a programmable digital signal processor. In a preferred embodiment, the digital FM demodulator and the digital audio processor are implemented as an integrated circuit. Methods for processing the audio signal using the digital processors of the invention are provided.

Abstract: Digital video contrast enhancement and skin tone correction by conversion to CIECAM02 color space with lightness transformation and a skin tone probability density function of hue and saturation.

Abstract: A method of color processing determines whether a pixel color is within at least one range of predetermined colors corresponding to a viewer expected color. If so, the method altering the pixel color to better approximate the viewer expected color. For detection of skin tones determining whether the pixel color is within a range of predetermined colors includes discounting an illuminant of the pixel color. The viewer expected colors are preferably skin tone, grass green and sky blue. The saturation level of grass green and sky blue are enhanced and that of skin tones are suppressed. The saturation s is limited based upon lightness J and hue h to convert to an allowable RGB color format range.

Abstract: Digital video contrast enhancement and skin tone correction by conversio to CIECAM02 color space with lightness transformation and a skin tone probability density function of hue and saturation.

Abstract: Digital video contrast enhancement and skin tone correction by conversio to CIECAM02 color space with lightness transformation and a skin tone probability density function of hue and saturation.

Abstract: Base band compensation for an IF stage in a television provides significant advantages over compensation applied to the composite signal. Each base band color difference signal is filtered to obtain cross-talk elements, which are then applied to the opposite channel to eliminate the cross-talk components from the color difference signal channels. The compensation technique is applicable to IF stages generally, including those based on SAW filters. High and low gain compensation of the cross-talk compensated signals may also be performed to reduce distortion in the compensated signals. The base band compensation tends to reduce or eliminate visual artifacts in a television image, especially where sharp contrast transitions occur in the image.

Abstract: System and method for an all-digital audio receiver for a BTSC MTS audio signal or other composite signal that is FM modulated. A preferred embodiment comprises a digital FM demodulator for receiving an analog to digital quantized SIF signal and performing demodulation and outputting a composite audio signal, and a digital audio processor for decomposing the composite audio signal into at least the SAP, stereo and monaural signals for audio reproduction. In a preferred embodiment, the digital audio processor is a programmable digital signal processor. In a preferred embodiment, the digital FM demodulator and the digital audio processor are implemented as an integrated circuit. Methods for processing the audio signal using the digital processors of the invention are provided.

Abstract: Systems and methods are provided for dividing two digital values. A look-up table provides a first output value in response to a value of an input signal. The first output value corresponds to a first estimate of a reciprocal for the value of the input signal. An approximation component provides a second output value corresponding to a second estimate of the reciprocal value for the value of the input signal as a function of the first output value and the value of the input signal. The look-up table is configured to provide the first output value within a predetermined error sufficient to enable the approximation component to improve the first estimate within a second predetermined error by the approximation component employing a single iteration of the function of the first output value and the value of the input signal.

Abstract: A system to reduce noise includes a noise measurement device that provides a measure of noise associated with a digital input video signal. A noise reduction filter provides a noise-reduced digital output video signal corresponding to the luma and chroma of the digital input video signal. The noise reduction filter has a parameter that varies on a pixel basis for the component of the digital input video signal as a function of the measure of noise. The range and sensitivity of the noise reduction can be user programmable.

Abstract: A method for optimizing a digital filter that produces an output signal from samples of an input signal is configured with filter coefficients that are selected by a prescribed filter coefficient search. The filter coefficient search uses a pre-scaling constant or an additive constant with the filter coefficients and canonical signed digits to reduce filter cost or filter execution time. The coefficient search includes a precision for the filter coefficients and an allowable number of nonzero digits for each coefficient to produce a filter coefficient set with a reduced overall number of nonzero digits. The resulting filter can generally be implemented with substantially less integrated circuit die area than that obtainable with previous design approaches.

Abstract: In a pipelined analog-to-digital converter (ADC) having an analog input signal and a digital output signal, and having a plurality of pipelined stages, each such stage having an analog input, an analog output comprising a residue voltage, and a digital output, the stage including a digital-to-analog converter substage having a plurality of capacitors and which are used in a sample-and-hold function and shuffled according to a predetermined procedure, a method for reducing noise generated from the shuffling when the capacitors are mismatched. The method includes the following steps. First, an estimation model is provided of the noise generated from the shuffling. The estimation model includes factors corresponding to mismatches of the capacitors. Mismatches among capacitors in the stage are estimated, based on the monitoring of an output parameter of the stage. A cancellation factor is generated by applying the mismatch estimations to the estimation model.