Abstract: A method and device for graphically representing the I and/or Q components of digitally modulated high frequency signal are described, in which the I or Q components measured in a temporally successive manner are graphically represented side-by-side on a display device.

Abstract: A system for providing an easily usable composite legality and component gamut display translates a video input signal into a plurality of component and composite format signals. A user selects from the plurality of component and composite format signals a pair of signals for input to the y-axis and x-axis of a rectangular plot. The resulting rectangular plot includes every pixel within a video frame of the video input signal and, together with prescribed limits, is displayed to provide a visual indication of composite legality and/or component gamut.

Abstract: A vector waveform correction device corrects a vector waveform displayed on a vector scope. A first color difference signal and a second color difference signal demodulated from a chrominance signal of a composite video signal are input as x and y, and a vector (x, y) is partially rotated in a unit of part of all the scanning lines.

Abstract: A phase shifter (70) for correcting the phase of a sub-carrier signal input into a decoder to a burst signal has a phase shift setting (5), a correction amount setting (9?), a phase shifter (6) and a 90-degree phase shifter (7). The phase shift setting (5) holds a phase shift amount for all the scanning lines. The correction amount setting (9?) holds a correction phase shift amount for every part of all the scanning lines. The phase shifter (6) partially shifts the phase of the sub-carrier signal in a unit of part of all the scanning lines, and shifts it in a unit of all the scanning lines, based on said phase shift amount and said correction phase shift amount. The 90-degree phase shifter (7) generates a sub-carrier signal orthogonal to said phase shifted sub-carrier signal.

Abstract: A vector waveform rotation device (60) for rotating a vector waveform displayed on a vector comprises rotation amount setting means (5?) for holding a rotation amount ?, and means (6?) for inputting a first color difference signal (B-Y signal) and a second color difference signal (R-Y signal) demodulated from a chrominance signal of a composite video signal as x and y, and rotating a vector (x, y) by generating a vector (x?,y?)=(x·cos ??y·sin ?, x·sin ?+y·cos ?) from the vector (x,y)=(first color difference signal, second color difference signal).

Abstract: A luminance qualified vector display device provides a vector display that is gated by a specified luminance range. In one implementation three luminance gates may be used, one for luminance levels above a specified high luminance threshold, a second for luminance levels below a specified low luminance threshold, and a third for luminance levels between the specified high and low luminance thresholds. Also the luminance thresholds for the medium luminance range may be separately adjusted to overlap the high and low luminance ranges respectively. Each luminance qualified vector display may be displayed separately, may be overlaid for display using a different color for each luminance range, or may be displayed in different quadrants of a display device or window together with the normal, non-luminance qualified, vector display.

Abstract: A method for testing the chroma performance of a digital rendering integrated circuit includes generating a video test signal where the video test signal has a constant luma amplitude, constant chroma amplitude, and varying chroma phase. The method then continues by modulating the video test signal with the digital rendering circuit, and displaying output from the digital rendering circuit.

Abstract: An artistic color gamut display is generated by obtaining maximum and minimum values for an RGB signal. The maximum and minimum values are used as X and Y values for an XY plot. A triangular graticule, or Spearhead display, is generated for the XY plot having a first side representing Lightness, a second side representing saturation and a third side representing Value. The area within the Spearhead display represents valid color gamut. The Spearhead display may be combined with more traditional displays, such as Vector or Arrowhead displays, to provide a completely three-dimensional analysis of the RGB signal in terms of the artistic parameters of Hue, Saturation and Value or Lightness.

Abstract: A digital signal transmission system using a digital modulation system comprising a digital signal transmitter having a first digital signal processing unit and a digital signal receiver receiving a digital signal from the transmitter, wherein the digital signal receiver comprising a second digital signal processing unit for processing the digital signal from the transmitter and outputting a digital demodulated signal and a correlation value signal, a signal converter coupled with the second digital signal processing unit and supplied the correlation value signal therefrom for generating a waveform indicating a transmission condition including a main wave in response to the correlation value signal, and a display coupled with the signal converter for displaying the waveform indicating a transmission condition in the digital transmission system.

Abstract: A vector waveform rotation device (60) for rotating a vector waveform displayed on a vector comprises rotation amount setting means (5′) for holding a rotation amount a, and means (6′) for inputting a first color difference signal (B-Y signal) and a second color difference signal (R-Y signal) demodulated from a chrominance signal of a composite video signal as x and y, and rotating a vector (x, y) by generating a vector (x′,y′)=(x·cos &agr;−y·sin &agr;, x·sin &agr;+y·cos &agr;) from the vector (x,y)=(first color difference signal, second color difference signal).

Abstract: An artistic color gamut display is generated by obtaining maximum and minimum values for an RGB signal. The maximum and minimum values are used as X and Y values for an XY plot. A triangular graticule, or Spearhead display, is generated for the XY plot having a first side representing Lightness, a second side representing saturation and a third side representing Value. The area within the Spearhead display represents valid color gamut. The Spearhead display may be combined with more traditional displays, such as Vector or Arrowhead displays, to provide a completely three-dimensional analysis of the RGB signal in terms of the artistic parameters of Hue, Saturation and Value or Lightness.

Abstract: A method for testing the chroma performance of a digital rendering integrated circuit includes generating a video test signal where the video test signal has a constant luma amplitude, constant chroma amplitude, and varying chroma phase. The method then continues by modulating the video test signal with the digital rendering circuit, and displaying output from the digital rendering circuit.

Abstract: A digital video signal monitoring apparatus comprises means (2,4,6) for receiving a digital video signal and extracting therefrom a plurality of digital signals, each of which comprises a plurality of successive digital sample values. The apparatus further comprises means (10) for interpolating additional digital values intermediate the successive samples of the or each extracted digital signal and means for displaying the waveform of the or each extracted digital signal as a series of discrete points corresponding to its respective digital sample values and interpolated digital values. Thus, none of the original signal information is lost in displaying a signal waveform having a substantially continuous appearance.

Abstract: Color monitoring apparatus has similarities to conventional vectorscope but utilizes unique color difference signals which are luminance independent. Linear combinations of ratios between R, G and B differences produce a display which maps color one-to-one to the plane of the display.

Abstract: A signal processing circuit for a vector scope adapted to display and measure characteristics of a color video signal on a screen which comprises a variable gain circuit 3, a demodulation circuit 6, timing signal generator 7, amplitude detection circuits 8,9, memory 12 storing a reference amplitude and CPU11. An input signal V.sub.in through the variable gain circuit is supplied to demodulation circuiting from where chrominance components R-Y, B-Y are provided to the amplitude detection circuits. When the timing signal is provided to the amplitude detection circuits, the circuits detect their amplitudes. The CPU computes an amplitude of a burst signal in accordance with the detected amplitudes and the difference between the computed amplitude and the reference amplitude stored in the memory. If the difference is not zero, the CPU controls the variable gain circuit so that it become zero.

Abstract: A clamping circuit for applying clamping to a signal having a plurality of components includes a frequency divider which frequency-divides a main clock signal of the clamping circuit by an even number when the plurality of components of the signal are odd in number and another frequency divider which frequency-divides the main clock signal of the clamping circuit by an odd number when the plurality of components of the signal are even in number. Manual adjustment of an optical black correction is provided which permits verification of an accurate optical black correction by monitoring color difference vectors on a vector scope.

Abstract: A composite signal-limit indicator for a component monitor converts an input video signal, such a digital 422 signal or a GBR signal, into composite Y and Mag C component signals The composite Y and Mag C component signals are presented on an X-Y display together with graticules that represent the locus of 100 IRE values and of -20 IRE values. Points of the composite Y and Mag C component signals that fall outside the arrowhead formed by the graticules indicate composite signal level violations for the input video signal. The composite Y and Mag C component signals are combined and compared with the limits represented by the graticules. The results of the comparison are latched for further processing to automatically provide the composite signal-limit indicator. The results of the comparison may also be used to generate a bright-up display on an image monitor that flickers to indicate the locations within the image represented by the input video signal where the composite signal level violations occur.

Abstract: A phase shifting device for a vectorscope is provided which enables a vector-displayed waveform to be instantaneously and accurately rotated to an arbitrary or variable predetermined target phase position, with an arbitrary or variable predetermined portion of the vector-displayed waveform being selected as a reference for phase shifting. The phase shifting device includes first and second phase shift input generators. The first generator produces a first phase shift input signal representative of an arbitrary amount of phase shifting. The second generator produces a second phase shift input signal representative of a predetermined amount of phase shifting for the instantaneous and accurate rotation of the vector-displayed waveform.

Abstract: A system for automatic generation of vector reference graticules for a vectorscope display acquires the active video portion of a video signal that includes a color bar test signal. The values for each color difference component at each reference color plateau for the acquired color bar test signal are averaged to provide horizontal and vertical displacement values for each reference color, including black. Graticule boxes are electronically generated and positioned for each reference color on a display according to the respective horizontal and vertical displacement values.

Abstract: Video cameras, such as charge coupled device cameras, are used for optically making dimensional measurements of laser beams. Such cameras have drawbacks including baseline offset error, shading error, pixel-to-pixel fixed pattern offsets, and poor signal-to-noise ratio. Methods and apparatus to correct for these errors, without losing any desired signal components, wherein the baseline offset error is corrected without the loss of any signal components that may otherwise be obscured due to noise. The baseline of the signal is raised above a digitizer's zero level, an average baseline without an input signal present is determined, and then the average baseline is subtracted from the subsequently obtained signals. The subtraction process is performed such that the subsequent frames in memory retain all negative signal components, as well as positive signal components, and thus there is no loss of the desired signal.