Abstract: Jitter of an overlay display with respect to the primary display of a television receiver is avoided by assuring that the vertical and horizontal blanking signal components are sufficiently time spaced by preventing the number of clock pulses occurring between the horizontal and vertical components of the blanking signal from going below a selected number. The number of clock pulses between the negative going transition of the vertical blanking signal and the positive going transition of the first horizontal blanking signal is tracked and when the number of pulses fails to exceed a reference value the number of pulses is changed to effectively shift the transitions with respect to one another.

Abstract: A digital input signal to be delayed is applied to a two-point linear interpolation filter which imparts delay to the signal proportional to the value of a delay control signal. Errors in both the amplitude and the phase of the delayed signal are minimized by the addition of a correction signal to the delayed signal. The correction signal is provided by applying the input signal to a further filter and a multiplier connected in cascade. The further filter is a linear phase filter having a response zero at zero frequency and a delay equal to an add multiple of one-half of the sampling period, Ts, of the digital input signal. The multiplier is controlled so as to vary the amplitude of the compensating signal as a non-linear function of the delay control signal so as to provide maximum amplitude compensation at delays corresponding to odd multiples of Ts/2 and zero amplitude compensation at delays equal to integer multiples of Ts.

Abstract: A slow motion system includes a variable interlace constant line-rate video camera, a variable speed recorder and a line-rate converter connected in cascade. During slow motion shooting the camera interlace ratio is increased, the recorder playback speed is reduced by the interlace ratio and the converter increases the line-rate of the recorded signal in proportion to the interlace ratio thereby providing a constant field-rate constant line-rate video output signal having a temporal resolution which increases as the interlace ratio increases.

Abstract: A solid-state imager for a television camera which generates a compatible wide-screen signal, i.e., a wide-screen signal with compressed left and right edge portions for each television line. The solid-state imager includes photosensitive picture elements (pixels) which are nonuniformly distributed in each row of the imager in accordance with the amount of compression desired in the left and right edge portions of the signal.

Abstract: A speed-up memory doubles the field rate of a video input signal by repeating each field to reduce flicker when the double field rate signal is displayed. Read/write clocks for controlling the memory are locked to the color subcarrier of the video input signal thereby tending to produce visual artifacts in the displayed image due to clock skew relative to sync when non-standard video signals are processed. The skew errors are corrected by circuitry which measures the skew of the read and write clocks and delays the video signal as a function of a difference between the clock skew measurements.

Abstract: The line rate of a video input signal is doubled for display in progressive scan fashion by dual mode processor which generates added lines for the display by interpolation when displaying normal television pictures and by replication (repeating lines) when displaying characters. The processor mode is automatically controlled by an image analyzer which identifies fields of text by counting "major" transitions of the video input signal occurring within a field and comparing the count with a threshold value. Errors in identification are minimized by a further counter which integrates the field count and a hysteresis detector which controls the processor operating mode in accordance with high and low limits of the integrated field count.

Abstract: A progressive scan receiver includes a frame interpolation filter for generating added lines for display in a given field from a video input signal by interpolation from corresponding elements of immediately preceding and following fields. A second filter provides a line interpolated signal having picture elements spatially and temporally coincident with corresponding elements of the frame interpolated signal and having a suppressed vertical detail component. A third filter attenuates the vertical detail component of the frame interpolated signal. An output circuit combines the signals of the three filters to provide a frame interpolated video output signal in which the vertical resolution of the video input signal is preserved and motion artifacts characteristic of frame interpolation are attenuated.

Abstract: A television receiver includes apparatus for stabilizing an on-screen character display by which the deflection signal source is controlled for operating in a free-running mode, substantially unaffected by signal variations on the sync input line, rather than in a synchronized mode when sync is unreliable or otherwise undesirable. As another feature, the deflection signal source is caused to operate at substantially the same frequency in either mode.

Abstract: A speed-up circuit time compresses and interlaces field delayed and interpolated lines of a video input signal for display in progressive scan fashion. The interpolated lines are produced by adding low and high frequency components derived from the video input signal. The low frequency component is produced by frame-combing and low pass filtering the input signal. The high frequency component is obtained by field delaying, line comb filtering and low pass filtering the input signal. The combined low and high frequency components are spatially and temporally coincident thereby reducing the visibility of motion artifacts (double images) on the display.

Abstract: A wide aspect ratio television system includes memories for storing and recovering a video input signal in response to read and write clock pulses, respectively. Write clock pulses are deleted to compress edge regions of a wide aspect ratio input signal and read clock pulses are deleted to restore the signal to its original aspect ratio. The pattern of delected pulses is altered on a line-by-line basis to reduce visible artifacts of signal decimation. Dual mode receivers include provisions for controlling edge blanking, interpolation and the pattern of clock pulses deleted as a function of received signals. Wide and standard aspect ratio images are displayed without altering the width of the display raster.

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 memory reverses the sequence of samples of selected lines of a composite video input signal without separating the color burst and chrominance components of the lines thereby preserving chroma-burst phase integrity of scrambled lines. A burst inserter adds a second color burst component to the normal and reversed sequence lines to preserve the secrecy of the scramble code. A descrambler includes a memory for restoring the sample sequence and removing the extra color burst component.

Abstract: A wide-aspect-ratio HDTV signal having 1600 luminance pixels/32 .mu.S line and 980 lines/frame is data reduced by deleting odd pixels of each line of TV field #1 and even pixels of each line of TV field #2 to produce 800 pixels per line, and is further data compressed by a form of differential-pulse-code modulation. The DPCM organizes the pixels into groups of five, and for each group transmits or records one reference pixel at full N-bits. The pixels to the right and left of the reference pixel are compared therewith to produce difference signals of M bits, where M<N. The remaining two pixels of each group are compared with reference pixels from the lines above and below to form M-bit difference signals. The difference signals are transmitted. The DPCM coding reduces the 800 pixels/line to the equivalent of 480 pixels/line. The color portion of the wide-aspect-ratio HDTV is similarly coded to produce the equivalent of 240 pixel/line.

Abstract: A progressively scanned video signal is encoded into temporal sum and difference components for transmission. The sum signal is temporally filtered, decimated and time expended to be compatible with interlaced receivers. The difference signal, also temporally filtered, decimated and time expanded, is conveyed via single or separate channels with the sum signal to a progressive scan receiver for reconstitution of the original progressive scan signal. Modified quadrature amplitude modulation is used to convey the sum and difference signals in a common channel.

Abstract: A receiver includes a line store progressive scan processor and a frame store progressive scan processor for doubling the line rate of a video input signal for display. The video input signal includes an identifying signal signifying whether the fields that are derived from a common scene. The identifying signal is detected and used to control a switch for selectively coupling the output of the processors to a display such that frame store processed signals are displayed for fields derived from exactly the same scene and line store processed signals are displayed for "mixed" fields (i.e., fields from different frames or frames containing motion).

Abstract: A motion detector for detecting motion in a picture contained in a television signal includes a filter that extracts a portion of the frequency spectrum of the television signal. The amplitude of the sidebands of the television signal in this portion of the frequency spectrum is indicative of motion in the picture scene. The signal from the filter is coupled to a peak detector that produces a motion indicative signal. The amplitude of the motion signal is proportional to the absolute value of the amplitude of the sidebands in this portion of the spectrum.

Abstract: A speed-up memory converts interlaced RGB input signals to double line-rate (progressive scan) form. A vertical detail signal is derived from the RGB input signals before or after speed-up and a vertical peaking signal is derived from the detail signal. During the first read operation of the speed-up memory both signals are added to the speeded-up signals to effect a preshoot of the resultant signal and during the second speed-up memory read operation only the peaking signal added to affect an overshoot of the resultant signals whereby alternate lines of the converted RGB signals exhibit enhanced vertical detail.

Abstract: A television system for generating a composite video signal for an image having extended aspect ratio such as 5:3, and for displaying such composite video signal in a television image area having the same extended aspect ratio. The horizontal blanking interval of an NTSC composite video signal is utilized for the transmission of video information characterizing either the right or the left edge of a display line of the picture; whereas, the remaining portion of the NTSC signal is utilized for the transmission of video information characterizing the inner portion of the display line between the edges. The video information for the missing edge in each display line is derived in the receiver from video edge information of adjacent display lines.

Abstract: A double scanning receiver includes a video speed-up memory with read and write clocks locked to multiples of burst. Visible artifacts tend to be produced when displaying non-standard video signals (e.g., from a VCR, game, computer, etc.) due to skew of the memory clock signals with respect to horizontal sync. Skew artifacts are corrected by delaying the output signal of the memory as a direct function of the read clock skew and as an inverse function of the write clock skew. The write clock skew is measured for each memory read and write cycle. The read clock skew for the first memory read cycle is obtained by doubling the write clock skew measured at the start of the first read cycle. The read clock skew for the second memory read cycle is obtained by adding the write clock skew measured at the start of the second read cycle to a measured half-period of the video input signal and doubling the fractional part of the sum thereof.

Abstract: A digital video signal processing circuit generates interlaced luminance and chrominance signals from interlaced composite color video signals. The interlaced luminance signal contains vertical detail information without peaking. Each of two progressive scan speed-up processors, controlled to operate in parallel, receives the interlaced luminance and chrominance signals. In each of the speed-up processors, the chrominance signals are time compressed and repeated to generate two lines of time compressed chrominance video for each line of interlaced chrominance video. Furthermore, in each of the speed-up processors, a vertical detail signal is regenerated that contains vertical detail information derived from the interlaced luminance signal. The vertical detail signal is nonlinearly processed to generate a vertical peaking signal that is combined with the vertical detail signal. A time compression stage speeds up the peaked vertical detail signal to a double line rate.