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14
Color Inspection
This chapter contains information about the color spectrum, color
matching, color location, and color pattern matching.
The Color Spectrum
The color spectrum represents the three-dimensional color information
associated with an image or a region of an image in a concise
one-dimensional form that can be used by many of the IMAQ Vision color
processing functions. Use the color spectrum for color matching, color
location and color pattern matching applications with IMAQ Vision.
The color spectrum is a one-dimensional representation of the
three-dimensional color information in an image. The spectrum represents
all the color information associated with that image or a region of the image
in the HSL space. The information is packaged in a form that can be used
by the color processing functions in IMAQ Vision.
Color Space Used to Generate the Spectrum
The color spectrum represents the color distribution of an image in the HSL
space, as shown in Figure 14-1. If the input image is in RGB format, the
image is first converted to HSL format and the color spectrum is computed
from the HSL space. Using HSL images directly, such as those acquired
with an IMAQ PCI/PXI-1411 image acquisition device with an onboard
RGB to HSL conversion for color matching, improves the operation speed.
© National Instruments Corporation
14-1
IMAQ Vision Concepts Manual