NI Video Measurement Suite

niVMS Analyse Camera VI

  • Updated2023-08-17
  • 5 minute(s) read

niVMS Analyse Camera VI

Performs an analysis of the composite signal output by an analog CCD camera.  Each type of measurement yields several video parameters that are displayed in the Results array (including name, value, and units). A graph of a relevant output waveform is displayed for most measurements and can be used for signal and measurement verification.

IMPORTANT NOTES:

  1. Before running this VI, ensure that desired video standard is configured, that video lines containing the appropriate test patterns have been acquired, and that the line selection made here matches accordingly. Failure to do this results in invalid measurements or a run-time error.
  2. Auto iris timing and external sync AC measurements require the digitizer to be specially configured for acquisition of nonvideo signals.

Measurement Type specifies the camera measurement to be performed.

Aperture
Auto Iris Level
Auto Iris Timing
BLC Windows
Blemishes
Chart Alignment
Colour Bars
Dust
External Sync AC
External Sync Pulse
External Sync Genlock
Horizontal Resolution
Levels
Orthogonality
Shading
Sharpness
Smear
Line Selection specifies the component type and block of lines to be analyzed in each stored frame.
CVBS channel specifies the index number of the acquired channel to be analyzed. The default value is 0.
start line specifies the number of the line or first line in each frame.
lines specifies the number of consecutive lines in each frame, starting at start line.
Additional Configuration contains configuration settings for miscellaneous measurements.
zone/group specifies the primary analysis zone for field-based (2-dimensional) measurements such as blemishes, edges, and levels, or the locations group for L=levels measurement.
spot span specifies the window span over which each amplitude measurement is averaged for certain measurements (auto iris level, shading).
amplitude threshold specifies the threshold level (in volts) used for certain measurements

BLC Windows Specifies the absolute level above which a BLC window is detected
Blemishes Specifies the level relative to the nominal pedestal above which a blemish is detected
Chart Alignment Specifies the absolute level above which the alignment box is detected
Dust Specifies the level relative to the nominal pedestal below which a dust particle is detected
External Sync Pulse Specifies the absolute level above which a sync pulse is detected
AC slope polarity specifies the slope of the AC waveform zero-crossing used for synchronization with the video signal in external sync AC measurements.
Genlock mode specifies the type of sync signal used for synchronization of two video signals in external sync genlock measurements. H sync timing differences are measured over a line, whereas V sync timing differences are measured over a field.
line averaging? specifies TRUE to enable noise reduction of the active line by averaging lines over all available frames. Only applies to camera measurements that can use it.
smoothing filter? specifies TRUE to enable noise reduction of the active line by applying a third-order smoothing. Only applies to camera measurements that can use it.
Colour Bars Configuration contains configuration settings for miscellaneous measurements.
black colour bar? specifies TRUE to enable measurement of the black luminance level, and FALSE to ignore the black bar from color bar analysis.
auto adjust Fsc? specifies TRUE to enable automatic adjustment of the subcarrier frequency (Fsc) for optimum detection of the color bar chrominance phase.
Error In describes error conditions that occur before this node runs. This input provides standard error in functionality.
Measurement Info contains general information about the measurement and how it was performed.
measurement name returns the full name of the measurement type performed.
test pattern analysed returns the names of the test pattern(s) or element(s) analyzed.
description returns a brief description of the measurement.
Averaging contains information about how much averaging was applied during the measurement.
measurements averaged returns the number of results (one from each line) averaged to produce a single measurement result.
lines per measurement returns the number of lines averaged prior to analysis. Lines from every frame can be time-averaged to produce a smoothed waveform to reduce noise before measurements are performed.
Waveforms contains measured waveforms relating to the measurement performed. It may be empty, or may contain one or more waveforms that illustrate certain features of the measured signal or outputs from the measurement itself.
Results returns an array of clusters containing the name (string), value (DBL), and units (string) for each result parameter.
Error Out contains error information. This output provides standard error out functionality.

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