National Instruments IMAQ Vision for Measurement Studio - Manual (Page 52)

Chapter 5 Machine Vision
IMAQ Vision for LabWindows/CVI User Manual 5-6 ni.com
1. Define a template that represents the part of the object that you want
to use as a reference feature. For more information about defining a
template, see the
Find Measurement Points section.
2. Define a rectangular search area in which you expect to find the
template.
3. Use the options parameter to select your options for finding the pattern
and the results that you want to overlay onto the image. When setting
the
Mode element, select IMAQ_MATCH_ROTATION_INVARIANT when
you expect your template to appear rotated in the inspection images.
Otherwise, select
IMAQ_MATCH_SHIFT_INVARIANT . Set the options
parameter to NULL to use the default options.
4. Choose the mode for the function. To build a coordinate transform for
the first time, set mode to
IMAQ_FIND_REFERENCE . To update the
coordinate system in subsequent images, set mode to
IMAQ_UPDATE_TRANSFORM .