National Instruments IMAQTM - Manual (Page 39)

Chapter 3 Making Grayscale and Color Measurements
IMAQ Vision for Visual Basic User Manual 3-10 ni.com
Specifying the Color Information to Learn
Because color matching only uses color information to measure similarity,
the image or regions in the image representing the object should contain
only the significant colors that represent the object, as shown in
Figure 3-5a. Figure 3-5b illustrates an unacceptable region containing
background colors.
Figure 3-5. Template Color Information
The following sections specify when to learn the color information
associated with an entire image, a region in an image, or multiple regions
in an image.
Using the Entire Image
You can use an entire image to learn the color spectrum that represents the
entire color distribution of the image. In a fabric identification application,
for example, an entire image can specify the color information associated
with a certain fabric type, as shown in Figure 3-6.
Figure 3-6. Using the Entire Image to Learn Color Distribution
a. b.