National Instruments IMAQ Vision for Measurement Studio - Manual (Page 6)

Contents
IMAQ Vision for LabWindows/CVI User Manual vi ni.com
Measure Color Statistics................................................................................................ 3-7
Comparing Colors ........................................................................................... 3-8
Learning Color Information ............................................................................ 3-9
Choosing the Right Color Information ............................................. 3-9
Specifying the Color Information to Learn ...................................... 3-10
Choosing a Color Representation Sensitivity ................................... 3-12
Ignoring Learned Colors................................................................... 3-13
Chapter 4
Blob Analysis
Correct Image Distortion ............................................................................................... 4-2
Create a Binary Image ................................................................................................... 4-2
Improve the Binary Image............................................................................................. 4-3
Removing Unwanted Blobs ............................................................................ 4-3
Separating Touching Blobs ............................................................................. 4-4
Improving Blob Shapes................................................................................... 4-4
Make Particle Measurements ........................................................................................ 4-4
Convert Pixel Coordinates to Real-World Coordinates ................................................ 4-7
Chapter 5
Machine Vision
Locate Objects to Inspect .............................................................................................. 5-2
Using Edge Detection to Build a Coordinate Transform ................................ 5-3
Using Pattern Matching to Build a Coordinate Transform ............................. 5-5
Choosing a Method to Build the Coordinate Transform................................. 5-7
Set Search Areas............................................................................................................ 5-8
Interactively Defining Regions ....................................................................... 5-8
Programmatically Defining Regions............................................................... 5-9
Find Measurement Points .............................................................................................. 5-9
Finding Features Using Edge Detection ......................................................... 5-9
Finding Lines or Circles ................................................................... 5-9
Finding Edge Points Along One Search Contour ............................. 5-11
Finding Edge Points Along Multiple Search Contours .................... 5-12
Finding Points Using Pattern Matching .......................................................... 5-13
Defining and Create Good Template Images ................................... 5-13
Training the Pattern Matching Algorithm ........................................ 5-15
Defining a Search Area..................................................................... 5-15
Setting Matching Parameters and Tolerances................................... 5-16
Testing the Search Algorithm on Test Images ................................. 5-18
Using a Ranking Method to Verify Results...................................... 5-18
Finding Points Using Color Pattern Matching ................................................ 5-18
Defining and Creating Good Color Template Images...................... 5-19