Measure Colors Controls

NI Vision Builder

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Measure Features Tab

Measure Colors Controls

Main Tab

The following controls are available on the Main tab.

Control Name Description
Step Name Name to give the step.
Region of Interest The region of interest you want to use for the step.
Reposition Region of Interest When enabled, the step dynamically repositions the region of interest based on a coordinate system you built in a previous step.
Reference Coordinate System Coordinate system to which you want to link the region of interest.

Histogram Tab

The following controls are available on the Histogram tab.

Control Name Description
Color Space Specifies which color space to use when calculating color measurements. The following options are available:
  • RGB—Uses the Red, Green, Blue color space and displays the resulting color histogram.
  • HSL—Uses the Hue, Saturation, Luminance color space and displays the resulting color histogram.
  • CIE L*a*b*—Uses the CIE L*a*b* color space and displays the resulting location on the CIE Color Gamut.
  • CIE XYZ—Uses the CIE XYZ color space and displays the resulting location on the CIE Color Gamut.
Note  Refer to Chapter 14 of the NI Vision Concepts Manual for more information about Color Spaces.
Color Histogram Displays the number of pixels at each intensity for the various color planes contained in the region of interest. The x-axis represents the color intensities, and the y-axis represents the number of pixels. This histogram only applies to RGB and HSL color spaces.
Note  Bright pixel intensities are represented with high numerical values. 255 is the maximum value. Dark pixels are represented with low values. 0 is the minimum value.
CIE Color Gamut Displays the location on the CIE Color Gamut for the average color components of the pixels in the region of interest. This color gamut applies only to CIE L*a*b* and CIE XYZ color spaces.
  • White Reference—CIE X, Y, and Z values associated with white. The default values of this control work with RGB values of 255, 255, 255 as white. This control applies only to CIE L*a*b* color space.
White Reference Specifies the CIE X, Y, and Z values associated with white. The default values of this control work with RGB values of 255, 255, 255 as white. This control applies only to CIE L*a*b* color space.
Results Displays the color measurements of the corresponding color space.
  • Average—Average color intensity of the pixels in the region of interest for the specified color plane.
  • Std. Dev.—Standard deviation of the intensity values. A higher value indicates a better distribution of the grayscale intensities in the region of interest. A lower value characterizes a region of interest with homogeneous pixel intensities.

Limits Tab

The following controls are available on the Limits tab.

Control Name Description
Color Plane Average When enabled, average intensity of pixels in the region of interest of the selected color plane must lie within the minimum and maximum values in order for the step to pass.
Color Plane Std. Dev. When enabled, standard deviation of pixels in the region of interest of the selected color plane must lie within the minimum and maximum values in order for the step to pass.
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