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TM
IMAQ
IMAQ Vision
TM TM
for LabWindows /CVI
User Manual
IMAQ Vision for LabWindows/CVI User Manual
August 2004 Edition
Part Number 371266A-01
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Support Worldwide Technical Support and Product Information ni.com National Instruments Corporate Headquarters 11500 North Mopac Expressway Austin, Texas 78759-3504 USA Tel: 512 683 0100 Worldwide Offices Australia 1800 300 800, Austria 43 0 662 45 79 90 0, Belgium 32 0 2 757 00 20, Brazil 55 11 3262 3599, Canada (Calgary) 403 274 9391, Canada (Ottawa) 613 233 5949, Canada (Québec) 450 510 3055, Canada (Toronto) 905 785 0085, Canada (Vancouver) 604 685 7530, China 86 21 6555 7838, Czech Repub
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Important Information Warranty The media on which you receive National Instruments software are warranted not to fail to execute programming instructions, due to defects in materials and workmanship, for a period of 90 days from date of shipment, as evidenced by receipts or other documentation. National Instruments will, at its option, repair or replace software media that do not execute programming instructions if National Instruments receives notice of such defects during the warranty per
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Contents About This Manual Conventions ...................................................................................................................ix Related Documentation..................................................................................................x IMAQ Vision...................................................................................................x NI Vision Assistant..........................................................................................x
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Contents Chapter 3 Making Grayscale and Color Measurements Define Regions of Interest............................................................................................. 3-1 Defining Regions Interactively ....................................................................... 3-1 Tools Palette Transformation ........................................................... 3-5 Defining Regions Programmatically............................................................... 3-6 Defining Regions
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Contents Defining a Search Area .....................................................................5-16 Setting Matching Parameters and Tolerances...................................5-17 Testing the Search Algorithm on Test Images..................................5-18 Using a Ranking Method to Verify Results......................................5-19 Finding Points Using Color Pattern Matching ................................................5-19 Defining and Creating Good Color Template Images .
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Contents Appendix A Technical Support and Professional Services Glossary Index IMAQ Vision for LabWindows/CVI User Manual viii ni.com
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About This Manual The IMAQ Vision for LabWindows/CVI User Manual is intended for ™ ™ engineers and scientists who have knowledge of the LabWindows /CVI programming environment and need to create machine vision and image processing applications using C functions. The manual guides you through tasks beginning with setting up your imaging system to taking measurements. Conventions The following conventions are used in this manual: » The » symbol leads you through nested menu items and dialog b
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About This Manual Related Documentation In addition to this manual, the following documentation resources are available to help you create your vision application. IMAQ Vision IMAQ Vision Concepts Manual—If you are new to machine vision and imaging, read this manual to understand the concepts behind IMAQ Vision. IMAQ Vision for LabWindows/CVI Function Reference—If you need information about IMAQ Vision functions while creating your application, refer to this help file. NI Vision Assista
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About This Manual Other Documentation Your National Instruments image acquisition (IMAQ) device user manual—If you need installation instructions and device-specific information, refer to your device user manual. Getting Started With Your IMAQ System—If you need instructions for installing the NI-IMAQ software and your IMAQ hardware, connecting your camera, running Measurement & Automation Explorer (MAX) and the NI-IMAQ Diagnostics, selecting a camera file, and acquiring an image, refe
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1 Introduction to IMAQ Vision This chapter describes the IMAQ Vision for LabWindows/CVI software, outlines the IMAQ Vision function organization, and lists the steps for making a machine vision application. Note Refer to the Vision Development Module Release Notes that came with your software for information about the system requirements and installation procedure for IMAQ Vision for LabWindows/CVI. About IMAQ Vision IMAQ Vision for LabWindows/CVI—a part of the Vision Development Module—is
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Chapter 1 Introduction to IMAQ Vision IMAQ Vision Function Tree The IMAQ Vision function tree (NIVision.lfp) contains separate classes corresponding to groups or types of functions. Table 1-1 lists the IMAQ Vision function types and gives a description of each type. Table 1-1. IMAQ Vision Function Types Function Type Description Image Functions that create space in memory for images and perform basic image Management manipulation. Memory Function that returns, to the operating system, previo
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Chapter 1 Introduction to IMAQ Vision Table 1-1. IMAQ Vision Function Types (Continued) Function Type Description Caliper Functions designed for gauging, measurement, and inspection applications. Operators Functions that perform arithmetic, logic, and comparison operations with two images or with an image and a constant value. Analytic Functions that perform basic geometric calculations on an image. Geometry Frequency Functions for the extraction and manipulation of complex planes. Functions
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Chapter 1 Introduction to IMAQ Vision Table 1-2. IMAQ Machine Vision Function Types (Continued) Function Type Description Measure Distances Functions that measure distances between objects in an image. Measure Intensities Functions that measure light intensities in various shaped regions within an image. Select Region of Interest Functions that allow a user to select a specific region of interest in an image. Creating IMAQ Vision Applications Figures 1-1 and 1-2 illustrate the steps for creat
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Chapter 1 Introduction to IMAQ Vision Set Up Your Imaging System Chapter 6: Calibrate Your Imaging System Calibration Create an Image Acquire or Read an Image Chapter 2: Getting Measurement-Ready Images Display an Image Attach Calibration Information Analyze an Image Improve an Image Improve an Image Make Measurements or Identify Objects in an Image Using 1 Grayscale or Color Measurements, and/or 2 Particle Analysis, and/or 3 Machine Vision Figure 1-1. General Steps for Designing a Vision Appl
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Chapter 1 Introduction to IMAQ Vision 2 Define Regions of Interest Chapter 4: Grayscale and Color Measurements Measure Measure Grayscale Statistics Color Statistics 3 4 Create a Binary Image Locate Objects to Inspect Chapter 5: Particle Set Search Areas Improve a Binary Image Analysis Find Measurement Points Identify Parts Under Inspection Chapter 6: Make Particle Measurements Machine Classify Read Read Vision Objects Characters Symbologies Convert Pixel Coordinates to Real-World Coordinates
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2 Getting Measurement-Ready Images This chapter describes how to set up your imaging system, acquire and display an image, analyze the image, and prepare the image for additional processing. Set Up Your Imaging System Before you acquire, analyze, and process images, you must set up your imaging system. How you set up your system depends on your imaging environment and the type of analysis and processing you need to do. Your imaging system should produce images with high enough quality so t
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Chapter 2 Getting Measurement-Ready Images 3. Select an IMAQ device that meets your needs. National Instruments offers several IMAQ devices, including analog color and monochrome devices as well as digital devices. Visit ni.com/imaq for more information about IMAQ devices. 4. Configure the driver software for your image acquisition device. If you have a National Instruments image acquisition device, configure the NI-IMAQ driver software through MAX. Open MAX by double-clicking the Measurem
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Chapter 2 Getting Measurement-Ready Images Table 2-1. IMAQ Vision for LabWindows/CVI Image Types Value Description IMAQ_IMAGE_U8 8 bits per pixel—unsigned, standard monochrome IMAQ_IMAGE_I16 16 bits per pixel—signed, monochrome IMAQ_IMAGE_SGL 32 bits per pixel—floating point, monochrome IMAQ_IMAGE_COMPLEX 2 × 32 bits per pixel—floating point, native format after a Fast Fourier Transform (FFT) IMAQ_IMAGE_RGB 32 bits per pixel—standard color IMAQ_IMAGE_HSL 32 bits per pixel—color IMAQ_IMAGE_RGB_
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Chapter 2 Getting Measurement-Ready Images Source and Destination Images Some IMAQ Vision functions that modify the contents of an image have source image and destination image input parameters. The source image receives the image to process. The destination image receives the processing results. The destination image can receive either another image or the original, depending on your goals. If you do not want the contents of the original image to change, use separate source and destination
