Rca Inc.

Rca Licensing Corporation

Robert F Casey

Hermann J Weckenbrock

Werner F Wedam

Leopold A Harwood

Kirk A Law

Barbara J Roeder

A picture-in-picture video signal generator includes a source of an auxiliary video signal, and a producer of successive samples representing the auxiliary video signals. A self-sequencing memory includes a data input terminal coupled to the producer of auxiliary video samples; a write address input terminal, for receiving an initial write address; a data output terminal and a read address input terminal for receiving an initial read address. Write control circuitry is coupled to the write address terminal of the self-sequencing memory, and generates initial write addresses in synchronism with horizontal line intervals of the auxiliary video signal. A source of a main video signal is also provided. Read control circuitry is coupled to the read address terminal of the self-sequencing memory, and generates initial read addresses in synchronism with horizontal line intervals of the main video signal. The main video signal is combined with samples from the self-sequencing memory to form a video signal representing a picture-in-picture image.

Picture-in-picture video signal generator

A picture-in-picture video signal generator includes a source of an auxiliary video signal, and a producer of successive samples representing the auxiliary video signal. A self-sequencing memory includes a data input terminal coupled to the producer of auxiliary video samples; a write address input terminal, for receiving an initial write address; a data output terminal and a read address input terminal for receiving an initial read address. Write control circuitry is coupled to the write address terminal of the self-sequencing memory, and generates initial write addresses in synchronism with horizontal line intervals of the auxiliary video signal. A source of a main video signal is also provided. An interlace inversion detector is coupled to the main and auxiliary video signal sources and produces an inversion detect signal indicating that an interlace inversion condition has been detected. Read control circuitry is coupled to the read address terminal of the self-sequencing memory, and generates initial read addresses in synchronism with horizontal line intervals of the main video signal and generates a modified sequence of initial read addresses in response to the inversion detect signal. The main video signal is combined with samples from the self-sequencing memory to form a video signal representing a picture-in-picture image.

Interlace inversion corrector for a picture-in-picture video signal

In an apparatus for displaying the picture information of an incoming interlaced television signal in noninterlaced raster scanning display on the faceplate of a picture tube, each video line of the television signal is separated into R, G and B color component signals. Each video line is compressed, or speeded-up, at a variable rate and delayed by a variable delay time to provide a speeded-up signal that is coupled to the corresponding electron beam gun of the picture tube. Each of the variable rate and delay is controlled in accordance with information relating to distortions of the raster scanning display. In this way, distortion, such as east-west or convergence, is reduced when the speeded-up signal is displayed.

Raster distortion correction circuit

A picture-in-picture image signal generator includes a source of an auxiliary video signal and an auxiliary synchronization component separator which produces an auxiliary odd/even field signal. Auxiliary image data is stored in a memory for subsequent retrieval. A source of a main video signal and associated synchronization component separator, which produces a main odd/even field signal, is also provided. A signal combiner combines a portion of the main video signal with data retrieved from the memory to form a picture-in-picture video signal. An interlace inversion detector generates a signal indicating an interlace inversion condition in response to the main and auxiliary odd/even field signals. A correction to the interlacing is made in response to the interlace inversion signal.

Interlace inversion detector for a picture-in-picture video signal

A pix-in-pix television signal processing system develops a composite video pix-in-pix signal representing a reduced-size auxiliary image insert in a full-sized main image. The auxiliary video signal is separated into luminance and chrominance components by filtering circuitry. The luminance signal is subsampled in a ratio of one to four and the chrominance signal, which is composed of two color difference signals modulating quadrature phase related subcarrier signals, is applied to circuitry which interpolates between selected pairs of samples to develop a frequency converted chrominance signal, representing the two quadrature phase related color difference signals modulating quadrature phase related subcarrier signals having frequencies that are one-quarter the frequency of the original subcarrier signal. The frequency converted chrominance signal and subsampled luminance signal are combined to generate a composite video signal representing the reduced-size auxiliary image. This signal is combined with the main signal to develop the composite video pix-in-pix signal.

Chrominance signal frequency converter as for a pix-in-pix television

As the 8-bit input signal applied to a threshold device reaches a first threshold level, the 1-bit output signal changes from a logical zero to a logical one. The 1-bit output signal is delayed by one system clock period and fed back. The delayed 1-bit output signal is combined (e.g., merged or added) with the 8-bit input signal, and the resulting signal is applied to the threshold device to provide a hysteresis feature. Once the delayed 1-bit output signal becomes a logical one, the input signal has to drop below a second, lower threshold level before the 1-bit output signal can revert back to a logical zero, whereby a margin of noise immunity is provided.

Digital threshold detector with hysteresis

An interlaced video input signal is applied to a speed-up unit which time compresses and interleaves lines of the input signal with lines of a further signal derived therefrom for display in progressive scan fashion on a display device. The further signal is generated by circuitry which derives line-interpolated, field-delayed and vertical detail signals from the input signal. Selection circuitry selects the field delayed signal for display when the detail signal is above a threshold level and the field-delayed signal is concurrently within a range bounded by the input signal and the line-delayed signal, the interpolated signal being selected for display otherwise to thereby provide a progressive scan display having relatively high vertical detail characteristic of interfield processing and immunity to motion artifacts characteristic of intra-field processing. Noise due to quantizing errors or poor input signal-to-noise conditions is further reduced by range extension circuitry which increases the selection range beyond the values bounded by the input and line-delayed signals for selection of the field-delayed signal.

Progressive scan display system having intra-field and inter-field

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.

Progressive scan processor employing interpolation in luminance channel

A transition detector is disclosed which compares comb filtered component signals from adjacent image lines. A detector detects signals in the band of frequencies normally occupied by color representative information for a given line and two adjacent lines. A control signal generator generates a control signal in response to the relative levels of the detected signals for the given line, and the lines adjacent the given line. The composition of the comb filtered component signal coupled from the comb filter to the component processing channel is altered in response to the generated control signal.

Image transition detector

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. Interimage motion represented by the chrominance component is detected by combining selected ones of interimage signal sums. The interimage signal sums are high pass filtered and applied to parallel combining elements which discriminate chrominance motion from vertical luminance transitions.

Video signal motion detecting apparatus

A television apparatus for displaying the picture information of an interlaced signal, such as a baseband NTSC signal, in a non-interlaced scanning format is described. When no picture change occurs, the picture information of the first and the second fields of the NTSC signal are displayed in alternate scan lines of the display of the apparatus, respectively, to form a picture frame during one vertical scanning interval. A signal, indicative that a picture change occurs in a section of the picture frame, is generated when a picture change occurs. The picture change indicative signal is obtained by using a frame comb filter to detect interframe picture variations. The picture change indicative signal causes the displayed picture information in that section of the picture frame to be derived from one field of the NTSC signal.

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Oradell, NJ, United States of America

Robert F Casey