Abstract: A system for reproducing a luminance signal from a medium containing a previously recorded luminance signal with a high-frequency portion thereof compressed in dynamic range includes a circuit for recovering that luminance signal from the medium. Filtering is done to separate the low-frequency and compressed-in-dynamic-range high-frequency portions of the recovered luminance signal from each other. A corer responds to the separated compressed-in-dynamic-range high-frequency portion of the recovered luminance signal to provide a cored high-frequency portion with expanded dynamic range and reduced noise.

Abstract: A memory addressing scheme suitable for use for either interleaving or de-interleaving data bytes of, e.g., a broadcast digital television (DTV) data stream. A number of memory branches are configured in a random access memory (RAM), wherein at least some of the branches have different numbers of memory locations for reading out and for storing data bytes, thus defining memory branches of different lengths in the RAM. A start address is determined for each of the memory branches in the RAM, corresponding to a first memory location of each branch. An offset value is determined for each memory branch, to be added to the start address for the branch for addressing a memory location of the branch. If an offset value does not exceed the length of a corresponding branch, an address corresponding to the sum of the branch start address and the offset value is generated for addressing a successive memory location of the branch, and the offset value for the branch is incremented by one.

Abstract: A system for reproducing a luminance signal from a medium containing a previously recorded luminance signal with a high-frequency portion thereof compressed in dynamic range includes a circuit for recovering that luminance signal from the medium. Filtering is done to separate the low-frequency and compressed-in-dynamic-range high-frequency portions of the recovered luminance signal from each other. A corer responds to the separated compressed-in-dynamic-range high-frequency portion of the recovered luminance signal to provide a cored high-frequency portion with expanded dynamic range and reduced noise.

Abstract: A system for reproducing a luminance signal from a medium containing a previously recorded luminance signal with a high-frequency portion thereof compressed in dynamic range includes a circuit for recovering that luminance signal from the medium. Filtering is done to separate the low-frequency and compressed-in-dynamic-range high-frequency portions of the recovered luminance signal from each other. A corer responds to the separated compressed-in-dynamic-range high-frequency portion of the recovered luminance signal to provide a cored high-frequency portion with expanded dynamic range and reduced noise.

Abstract: Apparatus useful in electronics for the tape recording of a video signal, which is a baseband signal of a prescribed bandwidth extending up to a prescribed maximum frequency, processes the video signal to generate a folded-spectrum video signal. The video signal is digitized and supplied to a digital band-splitting filter with a cross-over frequency at one-half said prescribed maximum frequency, for separating the digitized video signal into samples of a lower-frequency-band component and into samples of a higher-frequency-band component. A balanced modulator is connected for modulating a folding carrier wave of the prescribed maximum frequency, which modulation is done in accordance with the higher-frequency-band component to generate a balanced modulation signal; and the balanced modulation signal is linearly combined with the lower-frequency-band component to generate the folded-spectrum video signal.

Abstract: Apparatus useful in electronics for the tape recording of a video signal, which is a baseband signal of a prescribed bandwidth extending up to a prescribed maximum frequency, processes the video signal to generate a folded-spectrum video signal. The video signal is digitized and supplied to a digital band-splitting filter with a cross-over frequency at one-half said prescribed maximum frequency, for separating the digitized video signal into samples of a lower-frequency-band component and into samples of a higher-frequency-band component. A balanced modulator is connected for modulating a folding carrier wave of the prescribed maximum frequency, which modulation is done in accordance with the higher-frequency-band component to generate a balanced modulation signal; and the balanced modulation signal is linearly combined with the lower-frequency-band component to generate the folded-spectrum video signal.

Abstract: A frequency-multiplexed video signal is generated in which a color-under signal and a second under signal are linearly combined with at least partially overlapping frequency spectra to form a composite under signal for an FM luma signal. The frequency-multiplexed video signal is suited for recording on magnetic tape using helical scanning methods and for being played back from the magnetic tape using helical scanning methods. The second under signal is generated in such way that line-comb filtering can be used during playback to separate color-under signal and second under signal each from the composite signal despite their frequency spectra being at least partially overlapping in the composite signal.

Abstract: Noise estimation circuitry for estimating the noise in a small number of horizontal scanning lines of a video signal includes a lowpass line comb filter responding to said video signal, but not to chrominance-descriptive components thereof. The video signal free from chrominance-descriptive components is repeatedly sampled during the backporch interval of each horizontal scanning line, and the samples are accumulated to generate a revised noise estimate each successive horizontal scanning line.

Abstract: A method and apparatus for detecting image motion in a television signal obtained by conversion of film images to a sequence of television video fields using the 2-3 film pulldown technique, comprising generating a plurality of interim motion detection signals which are always based upon a comparison of image points in the video signal which are spaced two sequential fields apart, and gating the plurality of interim motion detection signals together in order to generate a final motion detection signal.

Abstract: Apparatus for spreading a control signal comprised of widening circuits for extending the control signal horizontally and vertically, a line signal spreading circuit for generating a ramp of increasing values during a given interval at the beginning of each extended control signal, maintaining the maximum value of the ramp for the remainder of the extended control signals and generating a ramp of decreasing values at the end of each extended control signal and also including a circuit for combining the signal values at corresponding points along a plurality of lines as the lines are scanned.

Abstract: A control signal spreader for ameliorating undesirable effects of abrupt changes in a control signal in a video signal processor gradually changes the magnitude of the control signal in the horizontal, vertical and temporal dimensions of the video signal. The control signal is applied to a first circuit, which, responsive to positive transitions of the control signal, generates a gradually increasing signal and provides the lesser valued one of the control signal and the generated signal. A delayed version of the control signal is applied to a second circuit, which, responsive to negative transitions of the control signal, generates a gradually decaying signal and provides the greater valued one of the control signal and the generated decaying signal. The first and second circuits are coupled to a third circuit which provides as an output control signal, the greater valued signal provided by the first and second circuits.

Abstract: Apparatus for estimating noise in an electrical signal having substantially redundant recurring intervals includes circuitry for producing difference samples corresponding to signal differences between the recurring redundant intervals. A number of difference samples are averaged, and ones of the difference samples contributing to each average are subtracted from the averages. Magnitude values are extracted from the differences between the averages and the difference samples. A predetermined number of the magnitude values are averaged to produce a noise estimate signal.

Abstract: A frame comb filter separates a luminance signal from a composite video input signal for display on every other line of a progressively scanned display. The filter includes a tap for providing a field delayed luma signal and an interpolator for providing a frame comb filtered and interpolated luma signal. A selector switch selects the field delayed luma signal for display on the intermediate lines of the display when the vertical detail content of the input signal is greater than a minimum threshold value and there is little or no interframe motion and selects the frame comb filtered and interpolated luminance signal for display otherwise thereby providing enhanced vertical detail and reduced field motion artifacts for displayed images.

Abstract: A motion detector for determining image motion in a video signal develops an array of signals representing the difference between pixels from adjacent frames. The array of signals are grouped into subarrays, each of which include the signal corresponding to the pixel under examination for motion. Each of the subarrays are independently examined to determine if the magnitude of all of the pixel differences represented in a particular subarray exceed a predetermined threshold and/or the pixel differences have like polarity. If these conditions are met in any one of the subarrays, a motion signal is produced.

Abstract: A motion detector for detecting interimage motion represented by composite video signals analyzes both the chrominance and luminance components for image motion. Interimage motion represented by the luminance component is determined from interimage signal differences. The interimage signal differences are separated into high and low frequency spectra corresponding to fine and coarse luminance image detail. Selected signal differences from the low frequency spectrum are summed and threshold detected to determine motion in the coarse image detail. The high frequency spectrum of the sample differences are applied to parallel summing circuits which sum different combinations of sample differences in order to discriminate motion signals from non-moving chrominance transitions. The detection signals from the high and low frequency motion detectors are combined to produce a luminance motion signal.

Abstract: A frame comb filter system having circuitry to minimize motion-induced artifacts in the reproduced image includes a line comb filter to extract a relatively high frequency luminance correction signal from frame comb filtered chrominance signal. This luminance correction signal, however, includes undesirable signal components due to vertical chrominance transitions even in the absence of motion. The system therefore includes circuitry to selectively recombine the high frequency luminance correction signal with frame comb filtered luminance signal only when motion occurs.