Abstract: Disclosed are apparatus and methods for denoising a video stream of a camera. A current frame of the video stream and a temporally adjacent frame of the video stream that has been previously spatially and temporally denoised are obtained. The current frame is first spatially denoised, while preserving edges in such current frame to generate a plurality of spatially denoised pixels for the current frame. A particular pixel of the current frame is then both spatially and temporally denoised based on a weighted averaging of the particular pixel's associated spatially denoised pixel from the current frame and a plurality of pixels from the temporally adjacent frame that have already been spatially and temporally denoised.

Abstract: A method of measuring peak signal to noise ratio (PSNR) of full color video, both total and component contributions as well as providing PSNR full color and component maps includes converting the components of the full color video for both reference and impaired video signals to RGB values, and computing the error energy for each of the G, B and R channels between the reference and impaired video signals. Each component contribution to the error for the full color video components is assessed by setting the other components to a reference value, such as zero. Also the total full color PSNR is computed in RGB. Finally a color residual PSNR map is generated and displayed together with the computed PSNR results to enable a user to visualize where the significant impairments occur in the impaired video.

Abstract: A receiver portion includes a bandpass filter (e.g. SAW filter) that performs channel selection from an input signal having a plurality of channels, and an image cancellation circuit that is in parallel with the bandpass filter. The bandpass filter performs channel selection to select a desired channel that falls in a passband of the bandpass filter. Since the passband is typically a few channels wide, the image channel falls outside the passband and is attenuated by the stopband attenuation of the bandpass filter. The image cancellation circuit includes an attenuator and a phase shifter. The attenuator is configured to have the same attenuation as the stopband attenuation of the bandpass filter at the image channel frequency, and phase shifter is configured to provide a phase shift of approximately 180 degrees. Therefore, the image cancellation circuit has an output that is equal in amplitude, but opposite in phase, to that of the bandpass filter at the image channel frequency.

Abstract: A spatio-temporal joint filter and a spatial joint filter for noise reduction are disclosed. The spatio-temporal joint filter includes a spatial joint filter including the first and second sub filters having different characteristics and includes a temporal joint filter. When the present invention is adequately used, an edge/detail region of an image is well preserved, an aggressive noise reduction is performed on a flat region, and the temporal flicker problems are eliminated. Additionally, it has an intrinsic motion compensation effect by using the spatio-temporal correlation between the adjacent frames.

Abstract: A circuit for moiré suppression detects the Nyquist frequency in an input video signal. Based on detected alternating structures indicative of the Nyquist frequency, the circuit fades between outputting the input video signal and a low-pass filtered version of the input video signal. When the output signal is applied to a video display, moiré is suppressed.

Abstract: A compensating method and apparatus is provided which collectively compensates for variations in a variety of characteristics in respective circuit portions of a signal processing circuit. A correction data generator is provided for generating correction value data for correction to be made for an output signal of the signal processing circuit, in order to compensate for variations in the characteristics of the at least one circuit portion. Also, a compensator is connected to receive an output signal from the signal processing circuit as well as to receive the correction value data from the correction data generating means, for correcting the output signal in accordance with the respective correction value data corresponding to the at least one circuit portion to generate a compensated output signal.

Abstract: A channel equalizer for a digital television receiver which filters an input signal to remove a noise component mixed therewith during transmission. The channel equalizer comprises an initial coefficient storage unit for outputting a predetermined coefficient to channel equalizer circuit when a certain channel is firstly selected. The predetermined coefficient is used as an initial filtering value for allowing the channel equalizer circuit to update a filtering coefficient so that it can converge on an optimum value. The stored filtering coefficient is output to the channel equalizer circuit when the firstly selected channel is again selected, so that it can be used as the initial filtering value.

Abstract: In a receiver for extended television signals in which a wide aspect ratio picture and at least one horizontal bar are jointly coded so as to form a standard aspect ratio picture, the at least one horizontal bar conveys vertical resolution enhancement information, and the extended television signal receiver includes an arrangement (107,111) for modifying the vertical resolution enhancement information to reduce an amount of distortions comprised therein, and an arrangement for combining the wide aspect ratio picture and the modified vertical resolution enhancement information to provide an enhanced wide aspect ratio picture.