Abstract: A display apparatus in which a marker signal created by combining primary color signals of predetermined levels in an arbitrary pattern and designating a specified area of a screen is detected, the screen is divided into a plurality of areas and a display formed of an image different in picture quality is present at each one of the plurality of areas, a control signal for suppressing the luminance of the marker signal is generated, to thereby make the marker signal inconspicuous.

Abstract: An apparatus and method useful in a test and measurement instrument for selecting a particular television field for display, determines the television system standard from the input signal, uses the standard selection to determine the time for one field, and multiplies the field rate by an operator-supplied number of fields to calculate the required holdoff time. The subject invention relieves the operator from turning the holdoff control multiple times, and also relieves the operator from having to calculate the time delays for any of one to seven fields of holdoff (in the case of a PAL signal).

Abstract: Method of evaluating degradation of electrical signals is disclosed. The method involves visually comparing a visual representation of a reference signal generated by a test signal source, which can be made identical to an original signal, and a degraded signal generated by another test signal source after passing through a video system.

Abstract: A luminance component extractor coupled to a source of a composite video signal including a luminance component. A sampler, coupled to the video signal source, produces samples representing a frame the video signal. A memory maintains minimum and maximum values of each sample in the frame of the video signal. A non-linear low pass filter, responsive to the minimum and maximum values, generates samples representing the luminance component.

Abstract: A waveform monitor receives HDTV and SDTV signals that are provided to a channel and an external trigger terminal respectively. An HDTV signal processor 14 produces a reference clock PCLK from the HDTV signal. A counter starts counting at the vertical sync signal of the SDTV signal and generates a trigger every time the count of the reference clock PCLK reaches a predetermined number (2,200, for example). This allows generation of a trigger signal which is phase locked to the vertical sync signal of the SDTV signal, and of which the frequency is the same as the horizontal line frequency of the HDTV signal. Therefore the waveform monitor can display the HDTV waveform line by line even though the HDTV and SDTV signals have different numbers of lines per field. The waveform monitor can be used to measure phase difference between television signals of difference formats, such as the HDTV and the SDTV.

Abstract: A system and method is provided for adjusting the performance of a display by adjusting a gray ramp to look like a neutral gray ramp, finding the white points of the display, and obtaining nonlinearity reference values for different colors each through adjusting the brightness of two pictures until the pictures disappear in background. The system and method according to the present invention requires no extra instruments or devices, and provides instructions on the display for easy operation with mouse or any input devices, thereby can be used by users without specialized knowledge to provide performance best fit users' requirements and application environment.

Abstract: A television simulator for DST transformers including a hood which is intended to be connected to a cathode ray tube of a television set. The television simulator further includes a first power supply connected to one of the terminals of the primary of the DST transformer for supplying power and a unit for simulating the final line stage of the television set. The unit for simulating the final line stage of the television set presents a first input signal from a microprocessor, a second input signal from the other terminal of the primary of the DST transformer, and first and second error output signals towards the microprocessor. The television simulator further includes a control unit for a display screen, the control unit receiving a signal from the microprocessor and also providing an output signal towards said display screen.

Abstract: A picture quality monitoring system for a television chain provides incremental metrics for each layer of the chain--video, compression and modulation. The output of each layer is stored as a reference signal for the next or subsequent layers. The output from each layer is compared with the output from a prior layer to determine an incremental degradation metric. All of the incremental degradation metrics may be combined to produce an overall degradation metric for the entire television chain.

Abstract: An ancillary data distribution display presents a graphic display in Cartesian coordinates of the video line numbers for a video frame from a serial digital video data stream along one axis and a data count for each line along the other axis for ancillary data extracted from the serial digital video data stream. The data count may represent packets of data, words of data or normalized delta values based upon the average number of data words per line for the video frame. The axis representing the data count is adaptive according to the maximum data count for the data type per video frame displayed. A particular line of the serial digital video data stream may be selected, with the graphical representation being highlighted as a cursor and the selected line number and the corresponding data count being displayed alphanumerically. The video frame may be split to provide two halves of the frame side-by-side on the display.

Abstract: A method for estimating a white point includes displaying a plurality of grey patches on a screen; requesting that a user select a patch corresponding to a neutral grey; and iteratively converging to a patch where the estimated white point is the most neutral grey point.

Abstract: An adjustment system for a video monitor including a microprocessor, a D/A converter, an on-screen display controller circuit and an operator input unit. The microprocessor is configured to output adjustment signals to input circuits of the video monitor via the D/A converter and overlay a message concerning image adjustment on a display screen via the on-screen display controller circuit. The adjustment system corrects the problem of conventional adjustment systems wherein adjustment operation cannot be carried out unless an operator is fully aware of and skilled in the adjustment procedure.

Abstract: A cable television monitoring system to monitor the return signals of a CATV system is disclosed. The system monitors the CATV system in a frequency range of 5-225 MHz and measures voltage and frequency parameters. The system provides an analysis in NTSC compatible base-band video which, when modulated to TV channel frequency and sent downstream in a cable TV system can be received at any point in a cable TV system.

Abstract: A signal waveform display system for displaying waveforms of one or two input signals on a display screen is provided which comprises first-third input switching circuits, first and second trigger generators, first and second horizontal sweep generators, and a composite horizontal sweet generator. The trigger generators respectively generates first and second trigger pulses synchronously with the input signals provided thereto through the first and second input switching circuits. The sweep generators are triggered by the trigger pulses and generate first and second sweep signals having variable time periods, respectively. The composite sweep generator generates a composite sweep signal including lower portions of the first sweep signal which are smaller than a reference voltage, and upper portions of the second sweep signal which are higher than the reference voltage.

Abstract: The pattern to be displayed on the display is constructed from at least three tone levels to display specific shapes such as letters and numeric characters. The pattern is designed so that the user will visually perceive different shapes when displayed at different display characteristics. The display characteristic is determined according to the user's perceived shape.

Abstract: An electrostatic probe device detects signals displayed on a cathode ray tube in a non-invasive manner. Specifically, the probe device includes a probe that is spaced from a fluorescent screen of a cathode ray tube by a dielectric material and a detection circuit coupled to probe. The detection circuit produces an output signal that corresponds to an input video signal supplied to the cathode ray tube. In a preferred embodiment, the probe is located directly on a face plate of the cathode ray tube, wherein the face plate acts as the dielectric material. Voltage fluctuations detected by the probe are equalized by the detection circuit. The detection circuit may also include amplification and inverter circuits, so that the output of the detection circuit can be supplied to a monitor for viewing. The image displayed on the monitor directly corresponds to the image displayed on the cathode ray tube.

Abstract: A method for detecting the characteristics of a display, comprises the steps of: creating a model of the display having multiple parameters relating the physical output of the display to an input signal creating the display; employing a model of the human visual system, generating a set of control signals for producing patterns in the display that enable an observer to employ visual selection criteria to identify specific patterns corresponding to specific values of the parameters; applying the set of control signals to the display to produce the patterns; selecting specific patterns from the display; determining the values of the parameters from the patterns selected; and determining the characteristics of the display by applying the values of the parameters to the model.

Abstract: Method and apparatus for non-invasively testing performance of a digital communication system. The test system finds particular application in digital broadcast systems where interruption of regular service for test purposes is impracticable. In one embodiment oriented to digital television cable broadcast systems, unwanted reflections due to loose connectors and other causes may be localized within a subscriber's home. The test system takes advantage of information typically generated by digital receivers to correct for communication channel imperfections. Examples of such information include current filter parameters computed for use in an internal adaptive equalizer, internal loop parameters, and the difference between the signal received and a reconstruction of that signal from the symbols estimated by the receiver.

Abstract: A system and method for evaluating video fidelity by calculating information frame rate. A time mechanism is sampled to obtain a time video signal. A visual excitation device is also sampled to obtain an information video signal. The time video signal is superimposed over the information video signal to produce a combined video signal. The combined video signal is transmitted over a system under test (SUT). The signal that exits the SUT is called a processed video signal. The processed video signal is analyzed to determined the information frame rate of the SUT.

Abstract: A serial digital video data analyzer combines a co-processor capable of handling the serial digital video data stream bit rate with a microprocessor operating at a slower bit rate. The co-processor includes a video feature detection/decision module that identifies specified errors or features from the serial digital video data stream and freezes the portion of the serial digital video data stream around such feature/error in a video data store. The co-processor may also insert a cursor into the serial digital video data stream prior to display on a monitor to indicate the position of indicated errors. The acquired serial digital video data is transferred to the microprocessor for an initial determination as to whether further processing is required.

Abstract: A system for compensating the output of an output device to eliminate reflected ambient illumination comprises a display device, a calibration memory, a reflectivity memory, a memory, a processor, an input device, a video card, and an achromatic card that serves as a standard for comparison to the output of the output device. The reflectivity memory stores the reflectivity characteristics of the output device. The calibration memory stores the optical characteristics of the output device. The memory stores the reflectivity characteristics of the achromatic card, data, and program instruction steps of the system. The output of the output device is adjusted to match the ambient illumination reflected from the achromatic card. The processor then determines the tristimulus values of the ambient illumination through the known tristimulus values of the output generated by the output device, the reflectivity characteristics of the achromatic card, and the reflectivity characteristics of the output device.

Abstract: A method and system for formatting characteristic CRT information into a standardized format to provide a dynamic CRT characteristic profile to enhance presently used methods of recalibrating CRTs is disclosed. Present CRT parameters are measured and combined with previously acquired calibration parameters in order to create updated characteristic information for the profile. The characteristic information includes the CRT color gamut, the white and black point of the CRT and the gamma of the CRT. In addition, ambient lighting conditions may be included in the profile. This characteristic information is stored in a CRT characterization profile in a standardized format. The profile is updated whenever the CRT is recalibrated or whenever the operating conditions of the CRT are changed. Further, the profile may be employed to recalibrate a destination CRT based on a source CRT's profile.

Abstract: An external data read/write circuit has a jack including serial clocks, serial data, bus stop, and power source lines installed on a television set and an external service card for writing corresponding area information into a memory of the television via a serial data line when an information transmission key input and a corresponding area code are received from the external service card, and for reading out information required for fault diagnosis from the television when a fault diagnosis key input is received to display the result on a display apparatus of the external service card, thereby writing information needed by a user into a memory or integrated circuit within the television and reading out fault information of the television.

Abstract: An apparatus for displaying line and frame waveforms having different time-scales of a video signal on a display screen is described which comprises complex sweep signal generating means including a line sweep signal generating circuit 2, a frame sweep signal generating circuit 3 and a switching circuit 4, and horizontal axis drive circuit including a horizontal location arrangement circuit 5 and a horizontal axis drive circuit 6. The line and frame sweep signal generating circuits 2 and 3 generate line and frame sweep signals S.sub.2 and S.sub.3 synchronously with line and frame synchronization signals of the video signal, respectively, and the switching circuit 4 alternatively transfers the line and frame sweep signals S.sub.2 and S.sub.3, synchronously with the frame synchronization signal to generate a complex sweep signal S.sub.4.

Abstract: A method and apparatus provides sweep control signals for an expanded display of a selected portion of a television signal. A first counter is preloaded with a number related to the position of the left hand edge of the selected portion of the waveform being monitored and a second counter is preloaded with a number related to the position of the right hand edge of the selected portion of the waveform. Clock pulses are counted by the first counter until the number preloaded therein is reached and then the second counter counts the clock pulses until the number preloaded therein is reached. Control signals are developed when each of the counters has counted the number preloaded therein.

Abstract: A method and system in a data processing system for modifying an image source data file to compensate for distortions resulting from a projection of an image source onto a surface that is not perpendicular to an image source projection system. A data processing system image source data file is identified and a test pattern is displayed utilizing a data processing system visual output device. A user is permitted to enter a distortion compensation factor, the displayed test pattern is modified utilizing the distortion compensation factor. Once a final distortion compensation factor is selected in response to the appearance of the modified test pattern, the data processing system image source data file is modified, utilizing the selected distortion compensation factor, thereby enhancing the projection of an image source onto a surface that is not perpendicular to an image source projection system.

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: An automatic adjustment circuit for an analog control unit comprising a detection circuit and a D/A control circuit, said detection circuit being connected to said analog control unit to detect gain errors in said analog control unit and to input a determination signal for the determination of the errors detected to a control microcomputer installed in the apparatus and said D/A control circuit is operated in response to receiving signal from said control microcomputer to accomplish the adjustment.

Abstract: Video cameras, such as charge coupled device cameras, are used for optically making spatial measurements. For example, such cameras are used for laser beam analysis. Such cameras also have drawbacks including baseline offset error and poor signal-to-noise ratio. By adjusting the baseline so that both noise and the desired signal produce only positive digital counts, deriving a baseline offset level with only noise, and then subtracting the baseline offset level from subsequent frames Containing data representing both noise and the desired signal, the baseline offset is corrected. With the baseline offset being corrected, signal-to-noise ratio improving techniques, such as frame averaging and results averaging, can be applied to extract the desired signals which would otherwise be buried in the noise. The method and apparatus is particularly suited to laser beam performance evaluations.

Abstract: The intensity output of a monochrome interlaced video monitor typically used in medical imaging may be tested as follows. The video card of a computer is controlled to output equal video intensity levels of red, green, and blue for a time sequenced series of different levels. These video signals are combined and attenuated such that the peak level of the series is about 700 mV, which is the industry standard for peak white on a monochrome monitor. The sync pulses from the video card are adjusted to about -300 mV, which is the industry standard for sync pulses driving a monochrome video monitor and are combined with the combined video signal to produce an intensity test signal for driving the monitor. The video card is controlled to produce a high line rate to drive video monitors having an (approximately double) high line rate and to produce a low line rate to drive video monitors having (an approximately double) low line rate.

Abstract: A method of collecting the spactial positions of crossing points of the lines in the grid on the visible portion of the screen of a television receiver used in different modes of operation includes the steps of storing a first set of correction values for each of the crossing points. The first correction values define the spactial positions of the correction points for all modes of operation of the television receiver. Additional correction values are stored for each mode of operation. The additional correction values are generated during an overscan period and during the scanning of an initialization line which is positioned outside the visible portion of the screen and compensate for displacement of the crossing points induced by tolerances in the tube. The first correction values and the additional correction values are simultaneously applied to the deflection current of the television tube while the visible portion of the screen is scanned.

Abstract: Correlation between a waveform displayed on a waveform display device and the corresponding portion of a video image displayed on a monitor is achieved by brightening a portion of a video input signal from which the waveform and video image are produced. A horizontal sweep signal is compared with voltages representing the left and right edges of the waveform display device screen to determine the portion of the video input signal that is "on-screen". The on-screen signal is combined with a line select signal to produce a control signal. The control signal is used to level shift the video input signal to provide a "bright-up" feature as part of the video image on the monitor, indicating the portion of the video image being displayed as a waveform on the screen of the waveform display device.