National Instruments IMAQ Vision for Measurement Studio S

Glossary

©NationalInstruments Corporation G-17 IMAQVision for LabWindows/CVI User Manual

rotation-invariant

matching

Apattern matching technique in which the reference pattern can be lo cated

atany orientation in the test image as well as rotated at any degree.

S

saturation Theamount of white added to a pure color. Saturation relates to the richness

of a color.A saturation of zero corresponds to a pure color with no white

added. Pink is a red with lowsaturation.

scale-invariant

matching

Apattern matching technique in which the reference pattern can be any size

in the test image. See shape matching.

segmentationfu nction Fully partitions a labeled binary image into non-overlapping segments,

witheach segment containing a unique object.

separation function Separates objectst hat touch each other bynarrow isthmuses.

shape matching Findsobjects in an image whose shape matches the shape of the object

specifiedby a shape template. The matching process is invariant to rotation

and can be set tobe invariant to the scale of the objects.

shift-invariant

matching

Apattern matching technique in which the reference pattern can be lo cated

anywherein the test image but cannot be rotated or scaled.

Sigma filter A highpass filtert hat outlines edges.

skeletonfunctio n Applies a succession of thinning operations to an object until its width

becomes one pixel.

skiz function Obtainslines in an image that separateeach object from the others and are

equidistantfrom the objects that they separate.

smoothing filter Blurs an image byattenu ating variationsof light in tensity in the

neighborhood of a pixel.

Sobelfilter Extractst he contours (edge detection) in gray-levelvalues using a

3×3 filterkernel. See gradient filter.

spatial calibration Assigningphysical dimensions to the area of a pixel in an image.

spatial filters Alterthe intensit y of a pixelwith respect to variations in intensities of its

neighboring pixels. Youcan use these filters for edge detection, image

enhancement, noise reduction, smoothing, and so forth.

Contents

Main IMAQ Page Important Information Warranty Copyright Trademarks WARNINGREGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS Conventions Contents Chapter 1 Introduction to IMAQ Vision Chapter 2 Getting Measurement-Ready Images Chapter 3 Grayscale and Color Measurements Chapter 4 Blob Analysis Chapter 5 Machine Vision Page Introduction to IMAQ Vision About IMAQ Vision Documentation and Examples Application Development Environments IMAQ Vision Function Tree Page IMAQ Machine Vision Function Tree Creating IMAQ Vision Applications Chapter1 Introductionto IMAQ Vision Figure1-2. InspectionSteps for Building a Vision Application IMAQVision for LabWindows/CVI User Manual 1-6 ni.com Getting Measurement-Ready Images Set Up Your Imaging System Calibrate Your Imaging System Create an Image Page Source and Destination Images AcquireorReadanImage Acquiring an Image Reading a File Converting an Array to an Image Display an Image Attach Calibration Information Analyze an Image Improve an Image Lookup Tables Filters Convolution Filter Nth Order Filter Grayscale Morphology FFT Page Complex Image Operations Grayscale and Color Measurements Define Regions of Interest Interactively Defining Regions Page Page Page Page Programmatically Defining Regions Defining Regions with Masks Measure Grayscale Statistics Measure Color Statistics Figure3-4. Primary Components of a Color Image Comparing Colors Learning Color Information Choosing the Right Color Information Specifying the Color Information to Learn Using the Entire Image Using a Region in the Image Using Multiple Regions in the Image Choosing a Color Representation Sensitivity Ignoring Learned Colors Blob Analysis Correct Image Distortion Create a Binary Image Improve the Binary Image Removing Unwanted Blobs Separating TouchingBlobs Improving Blob Shapes Make Particle Measurements Page Page Convert Pixel Coordinates to Real-World Coordinates Machine Vision Locate Objects to Inspect UsingEdgeDetectiontoBuildaCoordinateTransform Page Using Pattern Matching to Build a Coordinate Transform Page Chapter5 MachineVision NationalInstruments Corporation 5-7 IMAQVision for LabWindows/CVI User Manual ChoosingaMethodtoBuildtheCoordinateTransform Figure5-4. Buildinga Coordinate Transform Set Search Areas Interactively Defining Regions Programmatically Defining Regions Find Measurement Points Finding Features Using Edge Detection Finding Lines or Circles Figure5-5. Findinga Straight Feature Finding Edge Points Along One Search Contour Finding Edge Points Along Multiple Search Contours Finding Points Using Pattern Matching Defining and Create Good TemplateImages Symmetry Feature detail Positional information Background information Trainingthe Pattern Matching Algorithm Defining a Search Area Setting Matching Parameters and Tolerances Match Mode Minimum Contrast Rotation Angle Ranges Testingthe Search Algorithm on Test Images Using a Ranking Method to Verify Results Finding Points Using Color Pattern Matching Defining and Creating Good Color TemplateImages Color Information Symmetry Feature Detail Positional Information Trainingthe Color Pattern Matching Algorithm Defining a Search Area Setting Matching Parameters and Tolerances Color Sensitivity Search Strategy Color Score Weight Minimum Contrast Rotation Angle Ranges Testingthe Search Algorithm on Test Images Finding Points Using Color Location Convert Pixel Coordinates to Real-World Coordinates Make Measurements Distance Measurements Analytic Geometry Measurements Instrument Reader Measurements Display Results Page Calibration Perspective and Nonlinear Distortion Calibration Defining a Calibration Template Defining a Reference Coordinate System Page Page Learning Calibration Information Specifying Scaling Factors Choosing a Region of Interest Choosing a Learning Algorithm Using the Learning Score Learning the Error Map Learning the Correction Table Setting the Scaling Method Calibration Invalidation Simple Calibration Save Calibration Information Attach Calibration Information A Technical Support Resources Web Support NI Developer Zone Customer Education System Integration Worldwide Support Glossary Numbers/Symbols A B C Page D E F G H I Page J K L M N O P Page Q R S T Page Index A B C D E F G H I Page Page L M N O P R S T V W Z