Abstract: HDMI is a digital audio and video communications protocol commonly used in consumer electronics. HDMI is particularly synonymous with high fidelity audio and video. Even though HDMI is a digital communications protocol, the audio quality can be impaired by analog signal impairments and distortions even if there are no digital decoding errors. In particular, the very process by which the audio is converted from Digital (HDMI) to human audible “Analog Audio” can be prone to errors. This occurs when the Digital to Analog Converter (DAC) clock, which is derived from the HDMI TMDS clock or HDMI source, is “distorted” due to its jitter, resulting in erroneous sampling or outputting of vital audio samples, thereby reducing the audio quality of the experience. The present invention reduces the jitter on the TMDS clock, and hence the audio DAC clock, resulting in lower audio distortion.
Abstract: An image processing method for removing a noise component contained in an original image, includes: separating an original image into a temporary noise-free image and a temporary noise component; extracting an edge component in the temporary noise-free image by executing edge detection on the temporary noise-free image; determining a fine edge component in the original image contained in the temporary noise component based upon a level of the extracted edge component; extracting an actual noise component by excluding the fine edge component from the temporary noise component; and removing noise from the original image based upon the extracted actual noise component.
Abstract: A method for reducing color noises of a chrominance signal includes the following steps: receiving the chrominance signal; sampling the chrominance signal to generate a plurality of chrominance samples; determining a phase-rotation level between a specific chrominance sample and the chrominance samples; calculating an average value of the chrominance samples; and selectively outputting the average value or the chrominance information of the specific chrominance sample as an output chrominance information to represent the color information of the specific chrominance sample according to the phase-rotation level.
Abstract: Color correction is performed on a first set of three pixel values by determining a color phase of the pixel values. The determined color phase is used to determine a phase difference, and the phase difference is used to control an amount of color phase rotation applied to the chrominance pixel values of the first set. The color phase is also used to determine a first gain, and the first gain is used to control a scaling of the rotated chrominance pixel values, thereby generating color corrected chrominance pixel values. The color phase is also used to determine a second gain, and the second gain is used to control an amount of scaling applied to the luminance pixel value of the first set, thereby generating the color corrected luminance pixel value. How color phase determines phase difference, the first gain and the second gain is changed depending on lighting conditions.
Abstract: An NTSC system chrominance signal demodulation apparatus is provided with a clock timing change circuit for burst-locking an input signal under the state where the phase is shifted by 90 degrees for every line, and phase axis rotation circuits for performing phase axis rotation, thereby to enable conversion of the phase axis of the burst signal. Therefore, demodulation of a PAL system chrominance signal can be carried out as well as demodulation of an NTSC system chrominance signal, and thereby demodulation of chrominance signals can be carried out using a common device regardless of the broadcast systems such as NTSC and PAL. Further, demodulation of chrominance signals can be carried out even under adverse conditions such as weak electric field or level compression of the burst signal.
November 9, 2004
Date of Patent:
October 2, 2007
Matsushita Electric Industrial Co., Ltd.
Abstract: A chrominance signal demodulation circuit capable of precisely processing a chrominance signal demodulation even when a phase of an inputted chrominance signal is abruptly changed due to a tape track skew error. A first and second color difference signals in an R-Y axis and B-Y axis directions are obtained by multiplying a color burst signal of the inputted chrominance signal and color subcarrier signals generated by a color subcarrier generator. A demodulation phase detector 17 generates a phase error signal to compensate a phase difference between the phases of the color burst signal and the color subcarrier signal based on the first and second color difference signals obtained. The color subcarrier generator 12 generates color subcarrier signals compensated responsive to the phase error signal. Thereby, a chrominance information portion following to the color burst signal in the inputted chrominance signal is successively processed with a chrominance signal demodulation with a correct phase.
Abstract: A digital TV display device and method is disclosed including a display control unit providing selection signals, a look-up table unit having at least two look-up tables wherein at least one of the look-up tables is operative in a read mode and the other is operative in a write mode in response to the selection signals, and a look-up table selection unit forwarding a data read from the at least one look-up table operative in the read mode in response to the selection signals for displaying.
Abstract: In a video encoder, the color distortion between pixels can be reduced by encoding the hue transition to limit very large hue (phase) transitions and encode a corresponding smaller phase transition. This produces fewer spurious colors between pixels during the encoding. This can be done by comparing the change in hue value to a reference value and adding or subtracting 2 .pi. to this reference value to reduce the absolute value of a modified delta hue signal.
Abstract: A waveform shaping apparatus in which no unrequired waveform shaping operation is performed even if its sensitivity is enhanced is provided. A signal (A) to be shaped in waveform is delayed by delay circuits (1 and 2) to produce signals (B and C). The signals (A, B and C) are applied to an original correction signal generating means (200a) and a control signal generating means (100a) to produce original correction signals (Ka and Kb), and control signals (Ha and Hb), respectively. A control circuit (13) selects the original correction signals (Ka and Kb), or a value "0" in accordance with the control signals (Ha and Hb) to generate a quasi-correction signal (L). The signal (L) is multiplied by a specified coefficient in a coefficient multiplier (14) to produce a correction signal (M), and the correction signal (M) is added to the signal (B) in an adder (5) to obtain an output signal (N) which has been shaped in waveform.
March 30, 1993
Date of Patent:
April 4, 1995
Mitsubishi Electric Engineering Company Limited, Mitsubishi Denki Kabushiki Kaisha