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National Instruments Corporation
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IMAQ Vision for LabWindows/CVI User Manual
3
Grayscale and Color
Measurements
This chapter describes how to take measurements from grayscale and color
images. You can make inspection decisions based on image statistics, such
as the mean intensity level in a region. Based on the image statistics, you
can perform many machine vision inspection tasks on grayscale or color
images, such as detecting the presence or absence of components, detecting
flaws in parts, and comparing a color component with a reference.
Figure 3-1 illustrates the basic steps involved in making grayscale and
color measurements.
Figure 3-1.
Steps to Taking Grayscale and Color Measurements
Define Regions of Interest
A region of interest (ROI) is an area of an image in which you want to
focus your image analysis. You can define an ROI interactively,
programmatically, or with an image mask.
Interactively Defining Regions
You can interactively define an ROI in a window that displays an image.
Use the tools from the IMAQ Vision tools palette to interactively define and
manipulate an ROI. Table 3-1 describes each of the tools and the manner in
which you use them.
Define Regions of Interest
Measure
Grayscale Statistics
Measure
Color Statistics
