National Instruments IMAQTM - Manual (Page 59)

Chapter 5 Performing Machine Vision Tasks
© National Instruments Corporation 5-7 IMAQ Vision for Visual Basic User Manual
Choosing a Method to Build the Coordinate Transformation
Figure 5-4 guides you through choosing the best method for building a
coordinate transformation for the application.
Figure 5-4. Building a Coordinate Transformation
Start
Yes
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No
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Object positioning
accuracy better
than ±65 degrees.
The object under
inspection has a straight,
distinct edge (main axis).
The object contains
a second distinct edge not
parallel to the main axis in a
separate search area.
The object contains a
second distinct edge not parallel
to the main axis in the same
search area.
Build a coordinate
transformation based on
edge detection using two
distinct search areas.
Build a
coordinate transformation
based on edge detection
using a single search area.
Object positioning
accuracy better
than ±5 degrees.
Build a coordinate
transformation based on
pattern matching
shift invariant strategy.
Build a coordinate
transformation based on
pattern matching
rotation invariant strategy.
End
No