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IMAQ Vision Builder Tutorial

1. Chapter 1 System Requirements and Installation Installing IMAQ Vision Builder 3 Note To install IMAQ Vision Builder on a Windows NT or Windows 2000 system you must be logged in with Administrator privileges 2 Insert the IMAQ Vision Builder CD into your CD ROM drive If the CD startup screen does not appear use Windows Explorer to run the SETUP EXE program in the Setup directory on the CD Follow the setup instructions you see on your screen By default the IMAQ Vision Builder installation program creates a new folder Program Files National Instruments IMAQ Vision Builder 6 that contains the following items program folder IMAQ Vision Builder exe the online help file function libraries and other related program files readme txt Late breaking information about IMAQ Vision Builder xamples folder Images and scripts that you need to complete the example tutorials in this manual manuals folder Portable Document Format PDF versions of the IMAQ Vision Concepts Manual IMAQ Vision Builder Release Notes and this manual You must have Adobe Acrobat Reader installed to access these documents solutions folder Example images and scripts Launching and Exiting IMAQ Vision Builder To launch IMAQ Vision Builder in Windows point to Start Programs National Instruments IMAQ Vision Builder 6 To quit IMAQ Vision Builder follow these steps 1 2 3 IMAQ Vision Builder Tutorial Close an
2. Measurement of an object or distances between objects An image with monochrome information Functions that perform morphological operations on a grayscale image Indicates the quantitative distribution of the pixels of an image per gray level value Fills all holes in objects that are present in a binary image Color encoding scheme in Hue Saturation and Intensity G 4 ni com HSL HSV hue T O image image border Image Browser image definition image enhancement image file image format image palette image processing National Instruments Corporation G 5 Glossary Color encoding scheme using Hue Saturation and Luminance information where each image in the pixel is encoded using 32 bits 8 bits for hue 8 bits for saturation 8 bits for luminance and 8 unused bits Color encoding scheme in Hue Saturation and Value Represents the dominant color of a pixel The hue function is a continuous function that covers all the possible colors generated using the R G and B primaries See also RGB Input output The transfer of data to from a computer system involving communications channels operator interface devices and or data acquisition and control interfaces A two dimensional light intensity function f x y where x and y denote spatial coordinates and the value f at any point x y is proportional to the brightness at that point A user defined region of pixels surrounding an image
3. 3 10 W Web support from National Instruments A 1 getting help for IMAQ Vision 1 8 windows Acquisition 1 3 Parameter 1 4 Processing 1 4 2 3 Reference 1 4 2 3 3 11 Script 1 3 2 6 worldwide technical support A 2 Z Zoom In tool 4 7 IMAQ Vision Builder Tutorial
4. Functions that process pixels based on the value of the pixel neighbors require image borders An image that contains thumbnails of images to analyze or process in a vision application See pixel depth The process of improving the quality of an image that you acquire from a sensor in terms of signal to noise ratio image contrast edge definition and so on A file containing pixel data and additional information about the image Defines how an image is stored in a file Usually composed of a header followed by the pixel data The gradation of colors used to display an image on screen usually defined by a color lookup table Encompasses various processes and analysis functions that you can apply to an image IMAQ Vision Builder Tutorial Glossary image source image visualization imaging IMAQ inspection inspection function instrument driver intensity intensity profile intensity range intensity threshold JPEG K kernel IMAQ Vision Builder Tutorial Original input image The presentation display of an image image data to the user Any process of acquiring and displaying images and analyzing image data Image Acquisition The process by which parts are tested for simple defects such as missing parts or cracks on part surfaces Analyzes groups of pixels within an image and returns information about the size shape position and pixel connectivity Typical applications include quality of
5. IMAQ Vision are installed on your computer the wizard searches your machine and displays a list of the available LabVIEW and IMAQ Vision versions you can use to create the VI Select the target version of LabVIEW in the list and click Next IMAQ Vision Builder Tutorial prototyped from your hard disk Select Current Script to create a VI that performs the algorithm you Select the Image Source and the Acquisition Type then click Next Select Image File as the Image Source to create a VI to open an image ni com Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal 5 Check the parameters that you want to appear as controls inputs and indicators outputs on the front panel of the created VI Any unchecked parameters are hard coded as constants in the diagram 6 Click Finish to create the VI My Note You must have LabVIEW 6 or higher and IMAQ Vision 6 for LabVIEW or higher to use the LabVIEW VI creation features of IMAQ Vision Builder National Instruments Corporation 3 15 IMAQ Vision Builder Tutorial Using Gauging for Part Inspection This chapter describes gauging and provides step by step directions for prototyping a part inspection application in IMAQ Vision Builder What Is Gauging Tutorial Components such as connectors switches and relays are small and manufactured in high quantity Human inspection of these components is tedious and time consuming Vision systems can quickly and
6. Instrument Engineering Workbench Program development environment application based on the programming language G used commonly for test and measurement applications Represents the gray level distribution along a line of pixels in an image The image operations AND NAND OR XOR NOR XNOR difference mask mean max and min The brightness information in the video picture The luma signal amplitude varies in proportion to the brightness of the video signal and corresponds exactly to the monochrome picture See luma 1 Mega the standard metric prefix for 1 million or 10 when used with units of measure such as volts and hertz 2 Mega the prefix for 1 048 576 or 2 when used with B to quantify data or computer memory An automated application that performs a set of visual inspection tasks A number ranging from 0 to 1000 that indicates how closely an acquired image matches the template image A match score of 1000 indicates a perfect match A match score of 0 indicates no match Megabyte of memory Multimedia Extensions Intel chip based technology that allows parallel operations on integers which results in accelerated processing of 8 bit images IMAQ Vision Builder Tutorial Glossary morphological transformations neighbor neighborhood operations NI IMAQ 0 opening operators P palette pattern matching picture element pixel IMAQ Vision Builder Tutorial Extract and alter the str
7. Threshold End E Return vms lO ujelo mm alvia E 1 Script Tools 2 Script Window IMAQ Vision Builder Tutorial Figure 2 4 Thresholded Image The thresholding step is recorded in the Script window The script records the processing operation and all of its parameters If you need to run the same operation on other images you can save the script and use it again 2 6 ni com Chapter 2 Introduction to Image Processing with IMAQ Vision Builder 10 Select Script Save Script and name the script threshold scr If you find another image that you need to threshold similarly run this script on the image using the following steps a Load the image b Select Script Open Script to open threshold scr i c Click the Run Script button in the script window Try experimenting with different options and images For example you can perform a particle analysis to find the area that each object in this image occupies If you need help with any specific image processing operation click the Help button in the parameter window 11 Select File Exit to close IMAQ Vision Builder Acquiring Images in IMAQ Vision Builder IMAQ Vision Builder offers three types of image acquisitions snap grab and sequence A snap acquires and displays a single image A grab acquires and displays a continuous sequence which is useful for example when you need to focus your camera A sequence acquires image
8. and its path Select the Search Template tab Set Search Mode to Shift Invariant Use shift invariant matching when you do not expect the matches you locate to be rotated in their images If you expect your matches to be rotated use rotation invariant matching Check the Sub Pixel Accuracy checkbox Set the Minimum Score to 600 A minimum score of 600 ensures that IMAQ Vision Builder will find matches similar but not identical to the template Set Number of Matches to 1 With the Rectangle Tool draw an ROI around the left side of the bracket as shown in Figure 4 3 Be sure that the region you draw is larger than the template image and big enough to encompass all possible locations of the template in the other images you will analyze Drawing a region of interest in which you expect to locate a template match is a significant step in pattern matching It reduces the risk of finding a mismatch It also allows you to specify the order in which you want to locate multiple instances of a template in an image 4 4 ni com 12 13 14 15 National Instruments Corporation Chapter 4 Using Gauging for Part Inspection Figure 4 3 Selecting the First Search Area Once you draw the region of interest IMAQ Vision Builder automatically locates the template in the region and displays the score and location of the match Notice that the score for the match is 1000 The score for this match is perfect because you made the tem
9. and non circular are highlighted in red When you apply the threshold everything highlighted is set to 1 and all other pixels are set to 0 Tip You can adjust the pointers until all of the particles of interest are red The black pointer marks the minimum value and the white pointer marks the maximum value 4 Click OK to apply the threshold and add this step to the script Figure 3 3 shows the thresholded image The pixels that you selected for processing appear red Unselected pixels appear black The image is now a binary image which is an image composed of pixels with values of 0 and 1 This image is displayed using a binary palette which displays the pixel intensities of an image with unique colors All pixels with a value of 0 appear black and pixels set to 1 appear red The red pixels are now referred to as blobs or particles National Instruments IM W yee File Image Color Grayscale Binary Machine Vision Script Help Q Vision IMA Builder S mI Gale S o al o am mlela gt E 11 jpg 8 bit 512x512 Ka 4 gt ml ele Ti Binary A S 20 Toler la alam e Script plal 2 Retum Figure 3 3 Separating Particles from the Background with Thresholding National Instruments Corporation 3 7 IMAQ Vision Builder Tutorial Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal Modifying Blobs with Morphological Functions Morpholo
10. bracket measurements and the actual values you might see for the bracket images Notice that Bracket1 Bracket2 and Bracket3 are the only ones that meet the specifications The bold values for the other brackets indicate which measurements caused them to fail 3 Note The results you see in Excel may not match the values in Table 4 1 exactly However the results you obtain should be close enough to the values in Table 4 1 so that Bracket1 Bracket2 and Bracket3 pass inspection and Bracket4 Bracket5 and Bracket6 do not pass Table 4 1 Bracket Measurement Results Bracket Bracket Distance Bracket Angle Number acceptable range 362 368 pixels acceptable range 178 181 Bracket 1 363 00 179 8 Bracket 2 364 00 180 3 Bracket 3 363 00 179 7 Bracket 4 349 00 178 5 Bracket 5 339 01 178 4 Bracket 6 359 03 174 8 National Instruments Corporation 4 11 IMAQ Vision Builder Tutorial Technical Support Resources Web Support National Instruments Web support is your first stop for help in solving installation configuration and application problems and questions Online problem solving and diagnostic resources include frequently asked questions knowledge bases product specific troubleshooting wizards manuals drivers software updates and more Web support is available through the Technical Support section of ni com NI Developer Zone The NI Developer Zone at ni com zone i
11. distortion are corrected As you work with IMAQ Vision Builder you may need to consult other sources if you have questions The following sources can provide you with more specific information about IMAQ Vision IMAQ hardware and imaging IMAQ Vision Builder Online Help IMAQ Vision Builder offers tooltips and online help that you can access in the following ways National Instruments Corporation Access the IMAQ Vision Builder online help by selecting Online Help from the Help menu There you can find information not available in this manual such as function descriptions and directions for performing image processing functions Move the cursor over a button to see tooltips on buttons in the Processing toolbar Tools palette Script window Reference window Acquisition window or Image Browser Click the Help button in any function parameter window to get information about that function and its parameters 1 7 IMAQ Vision Builder Tutorial Chapter 1 System Requirements and Installation IMAQ Vision Documentation If you have purchased IMAQ Vision software from National Instruments you also have one of the following sets of documentation depending on the development environment you use e IMAQ Vision for LabVIEW IMAQ Vision for LabVIEW User Manual Contains information about how to build a Vision application using IMAQ Vision for LabVIEW IMAQ Vision for LabVIEW online help from inside the LabVIEW enviro
12. gt mje S Ts moe G9 Gray Levels D alA e 20 Tole S P alae By Script Filters Convolution Highlight De EB 512x512 1 1 _ Threshold Threshold Values Min 130 Max 255 o ology Ren le Image Source Help Auto Threshold Clustering Replace Auto Threshold Entropy Balete Retun Auto Threshold Metric J Dore E l Figure 3 7 Testing the Blob Analysis Script 6 Adjust the minimum threshold value until the blobs are clearly separated A minimum value of 150 works well 7 Click Replace 8 Click the Run Script button to rerun the script Notice that only the circular blobs now appear in the final processed image 9 Click Done to close the Particle Analysis window IMAQ Vision Builder Tutorial 3 12 ni com Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal Saving the Blob Analysis Script Now that you have written a blob analysis algorithm and tested it on another image you can save the script to use on similar images You also can perform batch processing with this script See the Analyzing a Collection of Images with Batch Processing section in Chapter 4 Using Gauging for Part Inspection for an example of batch processing in IMAQ Vision Builder 1 Select Script Save Script 2 Save the script as blob analysis scr Estimating Processing Time IMAQ Vision Builder can estimate the time in milliseconds that IMAQ Vision will take to proces
13. loaded into the processing window Preparing an Image for Blob Analysis IMAQ Vision Builder Tutorial Before you can separate circular particles from non circular particles you need to prepare the image To isolate particles of interest verify that individual particles are distinct from other particles that is there is a gap between particles and that the borders of those particles are distinct 3 2 ni com Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal Examining the Image Examine the image in the processing window The image is slightly blurred Also the edges of particles are not distinct Although you can see these problems from just looking at this image you may need to use a line profile in other cases A line profile returns the grayscale values along a line that you draw with the Line Tool from the Tools palette Follow these steps to examine edges using a line profile 1 Select Image Line Profile The parameter window appears and the Line Tool from the Tools palette is automatically selected and active 2 Draw a short segment across a particle as shown in Figure 3 1 Tip ROIs are context sensitive and you can easily adjust their location in the image or the position of their center points You can also adjust the position of the ROI in the image by using the arrow keys National Instruments Corporation 3 3 IMAQ Vision Builder Tutorial Chapter 3 Using Blob Analysis to Analyze the Struct
14. operator sets their values to 1 The pixels depicted in gray have values outside the threshold range The threshold operator sets their values to 0 From the Threshold parameter window specify settings that work best for your application To threshold this image set the Min value to 130 and Max value to 255 to select all of the objects Tip You may need to manipulate the parameters several times to find the values that work best Rather than entering numbers in the Min and Max fields you can select the range using the pointers on the histogram Adjust the pointers until all of the objects you want to select are red The black pointer marks the minimum value and the white pointer marks the maximum value National Instruments Corporation Click OK to apply the manual threshold to the image The image is converted to a binary image where all of the selected pixels in the threshold range are set to 1 red and all other pixels are set to 0 black 2 5 IMAQ Vision Builder Tutorial Chapter 2 Introduction to Image Processing with IMAQ Vision Builder Refer to Figure 2 4 to see what the image looks like after applying the threshold Sf National Instruments IMAQ Visi ak EM oat 15 x File Image Color Grayscale Binary Machine Vision Script Help we Metal jpg 8 bit 512x512 Ka j gt le gt al 4M o e J Binay T Tole P alam Script Begin Threshold Manual
15. parts analyzing defects locating objects and sorting objects A set of high level software functions such as NI IMAQ that control specific plug in computer boards Instrument drivers are available in several forms ranging from a function callable from a programming language to a virtual instrument VI in LabVIEW The sum of the Red Green and Blue primary colors divided by three Red Green Blue 3 The gray level distribution of the pixels along an ROI in an image Defines the range of gray level values in an object of an image Characterizes an object based on the range of gray level values in the object If the intensity range of the object falls within the user specified range it is considered an object Otherwise it is considered part of the background Joint Photographic Experts Group Image file format for storing 8 bit and color images with lossy compression extension JPG Structure that represents a pixel and its relationship to its neighbors The relationship is specified by weighted coefficients of each neighbor G 6 ni com L labeling LabVIEW line profile logic operators luma luminance machine vision match score MB MMX National Instruments Corporation G 7 Glossary The process by which each object in a binary image is assigned a unique value This process is useful for identifying the number of objects in the image and giving each object a unique identity Laboratory Virtual
16. technical support resources on our Web site and still cannot find the answers you need contact your local office or National Instruments corporate Phone numbers for our worldwide offices are listed at the front of this manual IMAQ Vision Builder Tutorial A 2 ni com Glossary Prefix Meaning Value p pico 10 7 n nano 10 9 u micro 10 6 m milli 10 3 k kilo 103 M mega 106 G giga 10 t tera 10 Numbers Symbols 3D Three dimensional 3D view Displays the light intensity of an image in a three dimensional coordinate area area threshold arithmetic operators system where the spatial coordinates of the image form two dimensions and the light intensity forms the third dimension A rectangular portion of an acquisition window or frame that is controlled and defined by software Detects objects based on their size which can fall within a user specified range The image operations multiply divide add subtract and remainder National Instruments Corporation G 1 IMAQ Vision Builder Tutorial Glossary binary image binary morphology binary threshold bit depth blob blob analysis blurring BMP border function brightness IMAQ Vision Builder Tutorial Bit One binary digit either 0 or 1 Byte Eight related bits of data an eight bit binary number Also denotes the amount of memory required to store one byte of data An image in whi
17. 1 4 purpose 2 3 using to browse images 3 11 remove border objects 3 8 Run Script button 2 7 3 11 3 12 S scripting batch processing 4 10 description 1 3 using example scripts 1 9 modifying scripts 3 12 opening scripts 2 7 Run Script button 2 7 3 11 3 12 saving scripts 2 7 3 13 Script window 1 3 2 6 testing scripts 3 10 ni com scripts blob analysis script recording 3 1 saving 3 13 testing 3 10 gauging script analyzing collection of images 4 10 saving 4 9 sample scripts 1 9 thresholding script 2 7 Select All Files option 3 2 4 3 Send Data to Excel button 3 10 separating particles from background 3 6 sequence 2 7 sequence acquisition 2 11 Show Labels option 3 10 simple calibration 1 7 simulation module 2 10 2 11 snap 2 7 snapping one image single acquisition 2 10 Solution Wizard 1 4 starting IMAQ Vision Builder 1 2 system integration by National Instruments A 1 system requirements 1 1 T taking measurements 4 7 technical support resources A 1 testing scripts 3 10 threshold 1 5 Threshold parameter window 2 4 thresholding manual threshold 2 4 3 6 modifying threshold parameters 3 11 procedure 2 4 separating particles from background 3 6 thumbnail view Image Browser 2 2 Tools Palette 1 4 National Instruments Corporation l 5 Index trigger 2 10 tutorials blob analysis 3 1 gauging 4 1 U using the caliper function 4 7 V Visual Basic
18. From this collection of images in the Image Browser you can select the image that you want to process Double click the first image Bracket 1 4pg to load it into the processing window Finding Measurement Points Using Pattern Matching Before you can compute the measurements you need to locate features on which you can base the measurements In this example you use pattern matching to find manufactured holes in a bracket These holes serve as measurement points from which you can determine whether the bracket s arch is the appropriate height and curvature National Instruments Corporation 1 Select Machine Vision Pattern Matching Make sure the Learn Template tab is selected With the Rectangle Tool click and drag a box around the left hole in the image as shown in Figure 4 2 The selected area or region of interest ROT will become the template pattern 4 3 IMAQ Vision Builder Tutorial Chapter 4 Using Gauging for Part Inspection IMAQ Vision Builder Tutorial 10 11 1 LN Figure 4 2 Selecting a Template Pattern Click Create from ROI to learn the selected area as the template pattern Learning the template takes a few seconds After IMAQ Vision Builder learns the template a save dialog box appears Navigate to Program Files National Instruments IMAQ Vision Builder 6 Examples Bracket Save the template as template png The Pattern Matching parameter window displays the template image
19. IMAQ IMAQ Vision Builder Tutorial NATIONAL December 2000 Editi N INSTRUMENTS Part Number 3222280 Worldwide Technical Support and Product Information ni com National Instruments Corporate Headquarters 11500 North Mopac Expressway Austin Texas 78759 3504 USA Tel 512 794 0100 Worldwide Offices Australia 03 9879 5166 Austria 0662 45 79 90 0 Belgium 02 757 00 20 Brazil 011 284 5011 Canada Calgary 403 274 9391 Canada Ottawa 613 233 5949 Canada Qu bec 514 694 8521 China Shanghai 021 6555 7838 China ShenZhen 0755 3904939 Denmark 45 76 26 00 Finland 09 725 725 11 France 01 48 14 24 24 Germany 089 741 31 30 Greece 30 1 42 96 427 Hong Kong 2645 3186 India 91805275406 Israel 03 6120092 Italy 02 413091 Japan 03 5472 2970 Korea 02 596 7456 Mexico 5 280 7625 Netherlands 0348 433466 New Zealand 09 914 0488 Norway 32 27 73 00 Poland 0 22 528 94 06 Portugal 351 1 726 9011 Singapore 2265886 Spain 91 640 0085 Sweden 08 587 895 00 Switzerland 056 200 51 51 Taiwan 02 2528 7227 United Kingdom 01635 523545 For further support information see the Technical Support Resources appendix To comment on the documentation send e mail to techpubs ni com Copyright 1999 2000 National Instruments Corporation All rights reserved 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 mate
20. OSE CUSTOMER S RIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART OF NATIONAL INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER NATIONAL INSTRUMENTS WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA PROFITS USE OF PRODUCTS OR INCIDENTAL OR CONSEQUENTIAL DAMAGES EVEN IF ADVISED OF THE POSSIBILITY THEREOF This limitation of the liability of National Instruments will apply regardless of the form of action whether in contract or tort including negligence Any action against National Instruments must be brought within one year after the cause of action accrues National Instruments shall not be liable for any delay in performance due to causes beyond its reasonable control The warranty provided herein does not cover damages defects malfunctions or service failures caused by owner s failure to follow the National Instruments installation operation or maintenance instructions owner s modification of the product owner s abuse misuse or negligent acts and power failure or surges fire flood accident actions of third parties or other events outside reasonable control Copyright Under the copyright laws this publication may not be reproduced or transmitted in any form electronic or mechanical including photocopying recording storing in an information retrieval system or translating in whole or in part without the prior written consent of National Instruments Corporation Tradem
21. OT BE RELIANT SOLELY UPON ONE FORM OF ELECTRONIC SYSTEM DUE TO THE RISK OF SYSTEM FAILURE TO AVOID DAMAGE INJURY OR DEATH THE USER OR APPLICATION DESIGNER MUST TAKE REASONABLY PRUDENT STEPS TO PROTECT AGAINST SYSTEM FAILURES INCLUDING BUT NOT LIMITED TO BACK UP OR SHUT DOWN MECHANISMS BECAUSE EACH END USER SYSTEM IS CUSTOMIZED AND DIFFERS FROM NATIONAL INSTRUMENTS TESTING PLATFORMS AND BECAUSE A USER OR APPLICATION DESIGNER MAY USE NATIONAL INSTRUMENTS PRODUCTS IN COMBINATION WITH OTHER PRODUCTS IN A MANNER NOT EVALUATED OR CONTEMPLATED BY NATIONAL INSTRUMENTS THE USER OR APPLICATION DESIGNER IS ULTIMATELY RESPONSIBLE FOR VERIFYING AND VALIDATING THE SUITABILITY OF NATIONAL INSTRUMENTS PRODUCTS WHENEVER NATIONAL INSTRUMENTS PRODUCTS ARE INCORPORATED IN A SYSTEM OR APPLICATION INCLUDING WITHOUT LIMITATION THE APPROPRIATE DESIGN PROCESS AND SAFETY LEVEL OF SUCH SYSTEM OR APPLICATION Conventions bold italic monospace The following conventions are used in this manual The symbol leads you through nested menu items and dialog box options to a final action The sequence File Page Setup Options directs you to pull down the File menu select the Page Setup item and select Options from the last dialog box This icon denotes a tip which alerts you to advisory information This icon denotes a note which alerts you to important information Bold text denotes items that you must select or click on in the software such a
22. See Figure 2 3 Thresholding an Image to view an example of the threshold Parameter window Reference window Displays the original version of the image image source as you manipulate it in the processing window See Figure 2 2 Processing an Image to view an image in the Reference window Tools palette Displays a collection of tools for selecting regions of interest ROIs zooming in and out and changing the Image palette See Figure 2 4 Thresholded Image to view the Tools palette Solution Wizard Displays a list of industries and corresponding quality assurance tasks that those industries perform Based on the task the user selects the wizard loads an IMAQ Vision based solution to the task Performance Meter Estimates how long your script will take to complete in IMAQ Vision on a given image LabVIEW VI Creation Creates the LabVIEW and IMAQ Vision VI corresponding to the algorithm you prototype in IMAQ Vision Builder Based on the options you select the LabVIEW VI creation wizard creates a new VI that implements the image processing steps of the current script or of a saved script file Image Analysis Functions IMAQ Vision Builder offers several image analysis functions including the following IMAQ Vision Builder Tutorial Histogram cCounts the total number of pixels in each grayscale value and graphs the result Line Profile Returns the grayscale values of the pixels along a line that you draw with the L
23. Vision Builder simulates the live acquisition process You can interact with the simulation module as you would with a live acquisition Gr 3 Click the Store Acquired Image in Browser button to send the image to the Image Browser 4 Click Return to return to the Image Browser 5 Process the image as you would any other image in IMAQ Vision Builder See Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal and Chapter 4 Using Gauging for Part Inspection for examples of processing images in IMAQ Vision Builder Grabbing an Image Continuous Acquisition 1 Make sure the Acquisition window is open IMAQ Vision Builder Tutorial 2 10 ni com gt 2 H Chapter 2 Introduction to Image Processing with IMAQ Vision Builder Click the Acquire Continuous Images button to acquire and display images in continuous mode at the maximum rate This operation is also known as a grab Click the Acquire Continuous Images button again to stop the acquisition and display the last acquired image Tip You can acquire a region of interest within the full sized image Draw a region of interest in your image while grabbing it and the image reduces to that area You can refine the acquired area again by selecting another region of interest or return to the full sized image by clicking on the image nE 4 Click the Store Acquired Image in Browser button to send the image to the Image Browser Click Return to return to the Im
24. a ONA P gt C Program Files Examples MetalMetall ipg 512x512 8 bits JPEG wm al ad mw gt tol om o Fall e m 1 Image Browser 2 Image Location 3 Browse Buttons 4 Thumbnail Full Size Toggle Image s Image Size 7 Image Type 6 Close Selected 8 File Format IMAQ Vision Builder Tutorial Figure 2 1 Image Browser You can view new images in either thumbnail view as shown in Figure 2 1 or in full size view which shows a single full size view of the selected image Click the Thumbnail Full Size View Toggle button to view the first image in full size 2 2 ni com Chapter 2 Introduction to Image Processing with IMAQ Vision Builder 6 To enter processing mode double click the image Metall jpg IMAQ Vision Builder loads the image into the processing window as shown in Figure 2 2 File Image Color Grayscale Binary Machine aaja vme s o y ision Script Help ulej Sr Metall jpg 8 bit 512x512 eT gt he Al Grey Level D A 5 20 Toler Pel alam Script Retum 512512171 4 1 Reference Window 3 Image Size 5 Processing Window 2 Script Window 4 Zoom Ratio Figure 2 2 Processing an Image Tip The Reference window displays the original version of the image as you manipulate it in the Processing window National Instruments Co
25. age Browser Process the image as you would any other image in IMAQ Vision Builder See Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal and Chapter 4 Using Gauging for Part Inspection for examples of processing images in IMAQ Vision Builder Acquiring a Sequence of Images 1 2 Hmi 3 Make sure the Acquisition window is open Set the properties for the Sequence property page Click the Sequence Acquisition button to acquire a sequence of live images A panel describing the status of the Sequence acquisition appears If you set the triggering action property to Disabled click the Start Acquisition button to begin acquiring a sequence of images Images acquired are automatically sent to the Image Browser 3 Note If your computer does not have an IMAQ board IMAQ Vision Builder simulates the live acquisition process You can interact with the simulation module as you would with a live acquisition 4 National Instruments Corporation Click Return to return to the Image Browser Process the image as you would any other image in IMAQ Vision Builder See Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal and Chapter 4 Using Gauging for Part Inspection for examples of processing images in IMAQ Vision Builder 2 11 IMAQ Vision Builder Tutorial Using Blob Analysis to Analyze the Structure of a Metal This chapter describes blob analysis and provides step by step directions fo
26. ages into IMAQ Vision Builder eee eeeeseceeeseeneeeeeeees 3 2 Preparing an Image for Blob Analysis 00 0 eee eeeeseeeeeeeeeeeeseeseeneeeaeenaes 3 2 Examining the Image wiccss s cssscecs seaeesedecsisteueescssaseutoeesssiassieveaszesvacteee 3 3 Filtering the Images cicc cciteecdatescandeds mann a inde a cucnacuecd neds 3 5 Examining the Results of the Filtering o oo eeeeeeeeereeeees 3 5 Separating Particles from the Background with Thresholding 00 3 6 National Instruments Corporation v IMAQ Vision Builder Tutorial Contents Modifying Blobs with Morphological Functions 0 cee eeeeeeeeseeeeeeeeeeee 3 8 Isolating Circular BlODS i i sc ssiisssevitee cdieseeasceteseesdns ceases eaeeteeaaas 3 9 Analyzing Circular Blobs 0 23 ccc c 5 secs cide teestaeeeeiet Rh seedeieesuseudie oeencenacecoeneeas 3 10 Testing the Blob Analysis Script 0 0 cece cece eeeeeseeeeceseeseeesecseeeseeseeneeeaeenaes 3 10 Saving the Blob Analysis Script ccc eeeeseeseceseeseeeceeseceeeeeesseeeseeseeeaeeaeees 3 13 Estimating Processing Time cece eeceeseceeceseeeeeeseeeseeseessecseeesecaeseeeeaeenaes 3 13 Creating a LabVIEW VI cez ccciesiec es a inaenea E abe elib R A A ie 3 14 Chapter 4 Using Gauging for Part Inspection Whats Gauging onoriano ir a GEE a she cache tert osaansetees 4 1 PULOTI al s aa R A A R E S E borers eee eget 4 1 Loading Images into IMAQ Vision Builder eect eeeeseeeeeneeeeeees 4 3 Finding Measu
27. arks IMAQ LabVIEW National Instruments and ni com are trademarks of National Instruments Corporation Product and company names mentioned herein are trademarks or trade names of their respective companies WARNING REGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS 1 NATIONAL INSTRUMENTS PRODUCTS ARE NOT DESIGNED WITH COMPONENTS AND TESTING FOR A LEVEL OF RELIABILITY SUITABLE FOR USE IN OR IN CONNECTION WITH SURGICAL IMPLANTS OR AS CRITICAL COMPONENTS IN ANY LIFE SUPPORT SYSTEMS WHOSE FAILURE TO PERFORM CAN REASONABLY BE EXPECTED TO CAUSE SIGNIFICANT INJURY TO A HUMAN 2 IN ANY APPLICATION INCLUDING THE ABOVE RELIABILITY OF OPERATION OF THE SOFTWARE PRODUCTS CAN BE IMPAIRED BY ADVERSE FACTORS INCLUDING BUT NOT LIMITED TO FLUCTUATIONS IN ELECTRICAL POWER SUPPLY COMPUTER HARDWARE MALFUNCTIONS COMPUTER OPERATING SYSTEM SOFTWARE FITNESS FITNESS OF COMPILERS AND DEVELOPMENT SOFTWARE USED TO DEVELOP AN APPLICATION INSTALLATION ERRORS SOFTWARE AND HARDWARE COMPATIBILITY PROBLEMS MALFUNCTIONS OR FAILURES OF ELECTRONIC MONITORING OR CONTROL DEVICES TRANSIENT FAILURES OF ELECTRONIC SYSTEMS HARDWARE AND OR SOFTWARE UNANTICIPATED USES OR MISUSES OR ERRORS ON THE PART OF THE USER OR APPLICATIONS DESIGNER ADVERSE FACTORS SUCH AS THESE ARE HEREAFTER COLLECTIVELY TERMED SYSTEM FAILURES ANY APPLICATION WHERE A SYSTEM FAILURE WOULD CREATE A RISK OF HARM TO PROPERTY OR PERSONS INCLUDING THE RISK OF BODILY INJURY AND DEATH SHOULD N
28. at isolates and keeps the circular blobs and removes the non circular blobs from the image 1 Select Binary Particle Filter 2 Select Heywood circularity factor from the list of particle filters This function calculates the ratio of the perimeter of the blob to the perimeter of the circle with the same area The more circular the blob the closer the ratio to 1 3 To find more circular and less oblong blobs enter a minimum value of 0 and a maximum value of 1 06 for the parameter range 4 Select the Keep Objects option to keep circular blobs and remove blobs that do not fit in this range 5 Click OK to add this step to the script The image now contains only circular blobs as shown in Figure 3 5 REE File Image Color Grayscale Binary Machine Vision Script Help sss IMAQ Vision SSS east zals vme S o ulala mm alwa eA Builder i1 jpg 8 bit 512x512 Ka 4 gt Te Tin g 7 Binary Dl al Alf a0 toe 2 2 alae By Script Begin Filters Convolution Highlight D Threshold Manual Threshold Adv Morphology Fill holes Adv Morphology Remove borde E Eleele Peun 512512171 4 Figure 3 5 Isolating Circular Blobs National Instruments Corporation 3 9 IMAQ Vision Builder Tutorial Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal Analyzing Circular Blobs Now that you have isolated circular blobs fo
29. certain value often 0 The number of values a pixel can take on which is the number of colors or shades that you can see in the image An image f x y that has been converted into a discrete number of pixels Both spatial coordinates and brightness are specified Increases the size of an object along its boundary and removes tiny holes in the object Software that controls a specific hardware device such as an IMAQ or DAQ device IMAQ Vision Builder Tutorial Glossary E edge edge contrast edge detection edge steepness erosion F fiducial function G gauging grayscale image grayscale morphology H histogram hole filling function HSI IMAQ Vision Builder Tutorial Defined by a sharp change transition in the pixel intensities in an image or along an array of pixels The difference between the average pixel intensity before and the average pixel intensity after the edge Any of several techniques to identify the edges of objects in an image The number of pixels that corresponds to the slope or transition area of an edge Reduces the size of an object along its boundary and eliminates isolated points in the image A reference pattern on a part that helps a machine vision application find the part s location and orientation in an image A set of software instructions executed by a single line of code that may have input and or output parameters and returns a value when executed
30. ch the objects usually have a pixel intensity of 1 or 255 and the background has a pixel intensity of 0 Functions that perform morphological operations on a binary image Separation of an image into objects of interest assigned a pixel value of 1 and background assigned pixel values of 0 based on the intensities of the image pixels The number of bits n used to encode the value of a pixel For a given n a pixel can take 2 different values For example if n equals 8 bits a pixel can take 256 different values ranging from 0 to 255 If n equals 16 bits a pixel can take 65 536 different values ranging from 0 to 65 535 or 32 768 to 32 767 Binary large object A connected region or grouping of pixels in an image in which all pixels have the same intensity level A series of processing operations and analysis functions that produce some information about the blobs in an image Reduces the amount of detail in an image Blurring commonly occurs because the camera is out of focus You can blur an image intentionally by applying a lowpass frequency filter Bitmap Image file format commonly used for 8 bit and color images extension BMP Removes objects or particles in a binary image that touch the image border 1 A constant added to the red green and blue components of a color pixel during the color decoding process 2 The perception by which white objects are distinguished from gray and light objects from dark object
31. chine Vision FUNCtiONS cee eesceeeeceseeeseeseeeeeeseeseeseeeseesseeseesesnseeaeenaes 1 6 Calibration FUNCHONS zeera noras ena a A E R 1 7 Getting Helper chek Se cele tA A a E a OE sates ghee devine 1 7 IMAQ Vision Builder Online Help sssseeessesessesseersseesesrereereresresesresreerssesrsees 1 7 IMAQ Vision Documentation cccccccssccesseecseseeeesseeeeesneeesseeeeeseeeesnesensaeees 1 8 National Instruments Web Site eee eeeeeeeseeeseeseeesecseesaeeeeeaeeneeeaes 1 8 IMAQ Vision Builder Scripts eee ccc eecesecseeesesseeesecsecseeeseenseeseenseeaeenaes 1 9 Chapter 2 Introduction to Image Processing with IMAQ Vision Builder Getting Started in IMAQ Vision Builder eee ceeeecseceeeeseeseeesecseeesesseenseeseenees 2 1 Acquiring Images in IMAQ Vision Builder eee eeeceesceceneceseeesceeeneeeeeeeeaeeesaeeeaeeeaes 2 7 Opening the Acquisition Window ou eee eeceeseeseeeseeseeeseceeceseceeeaeeeenaeenees 2 8 Snapping an Image Single Acquisition cceceeeeceeseeeeeeeseeeeseeseeeseeseees 2 10 Grabbing an Image Continuous Acquisition 0 0 0 cece eeeeeeeseeeeeeeeeeeeeees 2 10 Acquiring a Sequence of Images eeeeeseeeeceseeseeeseeseeeseeseeseeesesneeeaeenaes 2 11 Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal What Is Blob Analysis i ciscscssssssstsceses cieegectessspesobees sdecboescbaaneston coeds a E 3 1 T to al neinei e sabes weds E R E nadva ss dab A Ri sey 3 1 Loading Im
32. cles or it could be edges of a hole in the particle Later you threshold the image to make all of the pixels in the particles the same pixel value and perform a morphological operation on the image to fill any holes left in the particles 3 Click Close Filtering the Image Filters can smooth sharpen transform and remove noise from an image so that you can extract the information you need To sharpen edges including the edges of any holes inside a particle and create contrast between the particles and the background follow these steps 1 Select Grayscale Filters 2 Select Convolution Highlight Details from the Filters list This function looks for sharp transitions and highlights edge pixels according to a kernel to make gaps more prominent A kernel is a structure that represents a pixel and its relationship to its neighbors For more information about kernels see Chapter 5 Image Processing in the IMAQ Vision Concepts Manual Click Apply to add this step to the script 4 Click Close Examining the Results of the Filtering To confirm that the filter sharpened edges and separated particles perform another line profile using the following steps 1 Select Image Line Profile 2 Click and drag to draw a short segment across a particle to examine the line profile of a particle and its border as shown in Figure 3 2 The line profile indicates more defined edges 3 Click Close National Instruments Corporati
33. consistently measure certain features on a component and generate a report with the results From the results you can determine whether a part meets its specifications Gauging consists of making critical distance measurements such as lengths diameters angles and counts to determine if the product is manufactured correctly If the gauged distance or count does not fall within tolerance limits the component or part does not meet specifications and should be rejected Gauging inspection is used often in mechanical assembly verification electronic packaging inspection container inspection glass vile inspection and electronic connector inspection In this tutorial you analyze images of pipe brackets to see if the brackets meet their physical specifications A pipe bracket is a metal piece of hardware used to bolt down long slender parts such as a tube of bundled wires Your goal is to measure angles and distances between features on the brackets and determine if those measurements fall within a tolerance range Figure 4 1 illustrates the measurements and the acceptable values for those measurements National Instruments Corporation 4 1 IMAQ Vision Builder Tutorial Chapter 4 IMAQ Vision Builder Tutorial Using Gauging for Part Inspection Side View Bracket Distance 362 to 368 pixels Edge 1 Bracket Angle 178 to 181 degrees Edge 2 Width Center Top View Figure 4 1 Brack
34. e Grayscale Morphology Modifies the shape of objects in grayscale images using erosion dilation opening and closing functions e Threshold Isolates pixels that interest you and sets the remaining pixels as background pixels e Quantify Measures the intensity statistics of one or multiple regions in an image e Centroid Computes the energy center of a grayscale image or area of interest National Instruments Corporation 1 5 IMAQ Vision Builder Tutorial Chapter 1 System Requirements and Installation Binary Processing and Analysis Functions IMAQ Vision Builder contains functions for binary processing and analysis Binary Morphology Performs morphology transformations that modify the shape of objects in binary images Invert Binary Image Reverses the dynamic of an image that contains two different grayscale populations Particle Filtering Filters objects based on shape measurements Particle Analysis Computes more than 40 measurements on objects in an image including the area and perimeter of the objects Circle Detection Separates overlapping circular objects and classifies them according to their radii Machine Vision Functions IMAQ Vision Builder features several machine vision functions such as the following IMAQ Vision Builder Tutorial Edge Detection Finds edges along a line that you draw with the Line Tool from the Tools palette Find Straight Edge Finds points within the edge of an object a
35. e caliper measurements to the script and close the caliper window 14 Select Script Save Script and save the script as bracket scr National Instruments Corporation 4 9 IMAQ Vision Builder Tutorial Chapter 4 Using Gauging for Part Inspection Analyzing a Collection of Images with Batch Processing Perform the following steps to run the script as a batch process on the bracket images and generate a text file containing all of the measurement data 1 2 Select Script Batch Processing Select Browser from Image Source to process the images stored in the Image Browser The listbox contains all of the steps in the script You can select any step in the script and choose options such as saving that step s results to file displaying results or opening the parameter window to adjust the settings on each iteration For this example open the caliper parameter window and save the caliper results to a file Select the last caliper entry in the list box Check Open Results Panel and Save Results under Analysis Mode Click the Setup button and set the following options a Select One file for all results b Press the Browse button navigate to the directory where you want the file saved and click Select Cur Dir c Inthe File Name Prefix box type bracket txt to give the results files a consistent name Click OK to close the Setup options Click Run to start the batch process As batch processing runs a progress wi
36. e edges that you can use to calculate Width Center as shown in Figure 4 5 IMAQ Vision Builder labels the edges 1 and 2 0 Tip To draw a straight line press and hold the lt Shift gt key as you draw the line IMAQ Vision Builder Tutorial Figure 4 5 Finding the Edges for Bracket Distance Look at the line profile The sharp transitions in the line profile indicate edges Notice that the number of edges found is displayed under the line profile Click Apply to add this edge detection step to the script Click Close to close the Edge Detector window 4 6 ni com Chapter 4 Using Gauging for Part Inspection Taking the Measurements Now that you have found the bracket s holes and the necessary edges you can calculate the center of the bracket s width distance between the bracket s holes and angle of the bracket s arms with the caliper function The caliper function is a tool that uses points on the image to calculate measurements such as distances angles the center of a segment or the area depending on the number of points you have selected on the image These points are results of earlier processing steps such as edge detections and pattern matching Follow these steps to make the measurements 1 Select Machine Vision Caliper 2 In the image click on points 3 and 4 to obtain the first measurement Width Center which specifies the center of the bracket s width Q Tip If you have trouble finding the p
37. ent for your application 1 8 ni com Chapter 1 System Requirements and Installation The NI Developer Zone at ni com zone is the essential resource for building measurement and automation systems At the NI Developer Zone you can easily access the latest example programs system configurators tutorials technical news as well as a community of developers ready to share their own techniques IMAQ Vision Builder Scripts You installed several example scripts when you installed IMAQ Vision Builder You can run these scripts to learn more about IMAQ Vision Builder scripting capabilities You also can customize these scripts for your own applications By default the scripts are installed at Program Files National Instruments IMAQ Vision Builder 6 Examples and at Program Files National Instruments IMAQ Vision Builder 6 Solutions National Instruments Corporation 1 9 IMAQ Vision Builder Tutorial Introduction to Image Processing with IMAQ Vision Builder This chapter describes how you can use IMAQ Vision Builder to create and test your own image processing algorithms It explains how to get started in IMAQ Vision Builder For detailed information about digital images see Chapter 1 Digital Images in the IMAQ Vision Concepts Manual Getting Started in IMAQ Vision Builder This section describes the software specific terminology that you need to complete the tutorials in this manual and understand the online help The best way t
38. es for a Sequence acquisition For information about the properties of other IMAQ boards see your hardware manual and the MAX online help National Instruments Corporation Number of Frames Number of frames you want to acquire Skip Count Number of frames you want to skip between acquisitions Line Physical trigger line 2 9 IMAQ Vision Builder Tutorial Chapter 2 Introduction to Image Processing with IMAQ Vision Builder e Action Triggering action Disabled Disables triggering Trigger start of acquisition Trigger each image e Timeout Time in milliseconds within which the trigger must occur 3 Note A trigger is any signal that causes or starts some form of data capture e To set any other property of your image acquisition board or your camera select the board or channel in the list then click the MAX button to display the corresponding MAX property window See the MAX online help for more information on the MAX property windows 3 Note Your computer must have a National Instruments IMAQ image acquisition board and NI IMAQ 2 5 or higher installed before you can acquire live images in IMAQ Vision Builder Snapping an Image Single Acquisition 1 Make sure the Acquisition window is open 2 Click the Acquire Single Image button to acquire a single image with the IMAQ board and display it This operation is also known as a snap 3 Note If your computer does not have an IMAQ board IMAQ
39. es in the bracket and determines whether the bracket s arch is the appropriate height Select Distance from the Type of Measure list 9 Click the Measure button to compute the distance between the bracket s holes and add the measurement to the results table IMAQ Vision Builder Tutorial 4 8 ni com Chapter 4 Using Gauging for Part Inspection 10 Click on points 1 5 and 2 in that order to find the third measurement Bracket Angle which measures the angle of the bracket s arms with respect to a vertex at point 5 as shown in Figure 4 7 11 Select Angle from the Type of Measure list 12 Click the Measure button to compute the angle of the bracket s arms and add the measurement to the results table Figure 4 7 shows the image with Bracket Distance and Bracket Angle selected on the image and displayed in the results table Y National Instruments 10 x K Q Vision File Image olor Grayscale Binan Machine Vision Script Help er eee ee EE y HPR y al Bracket jpg 8 bit 572x336 KRAAL Te a AAEE Toler 2 alam Script Centeri 0 274 00 r 156 32 fF Begin Angle 179 9 Pattern Matching Pattern Matching Edge Detector First amp Last Edge BACEGME 2 Pattern Matching 3 Edge Detector 4 Edge Detector a Select 2 points Retum or more plajele Figure 4 7 Using the Caliper Tool to Collect Measurements 13 Click Apply to add thes
40. esholding National Instruments Corporation 3 1 IMAQ Vision Builder Tutorial Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal Remove all objects touching the border so that you remove partial particles Use a particle filter to find all circular blobs and remove non circular blobs Perform a particle analysis to find the total area occupied by circular blobs Loading Images into IMAQ Vision Builder 1 If IMAQ Vision Builder is not loaded launch the application from the Start menu Start Programs National Instruments IMAQ Vision Builder 6 Click the Open Image button from the Welcome Screen If you already have IMAQ Vision Builder running press the Open Image button in the toolbar Navigate to Program Files National Instruments IMAQ Vision Builder 6 Examples Metal and check the Select All Files option IMAQ Vision Builder previews the images in the Preview Image window and displays information about the file format size and pixel depth 0 Tip The Preview Image window displays all selected images in a sequence To view the images at a different rate adjust the slide to the right of the Preview Image window Click OK IMAQ Vision Builder loads the image files which represent microscopic views of pieces of metal into the Image Browser From this collection of images in the Image Browser you can select the image that you want to process Double click the first image Metal1 4jpg The image is
41. et Specifications Width Center is the center of the bracket s width Width Center becomes the vertex of Bracket Angle Bracket Angle measures the angle of the arms of the bracket and determines if the bracket s arms are aligned properly Bracket Distance measures the length in pixels between two manufactured holes in the bracket Bracket Distance also determines whether the bracket s arch is the appropriate height and curvature As you perform this analysis IMAQ Vision Builder records all of the processing operations and parameters in a script You will run that script on other bracket images to determine which are good and which are defective 4 2 ni com Chapter 4 Using Gauging for Part Inspection Loading Images into IMAQ Vision Builder Perform the following steps to load an image 1 Launch IMAQ Vision Builder from the Start menu Start Programs National Instruments IMAQ Vision Builder 6 Select File Open Image to load images Navigate to Program Files National Instruments IMAQ Vision Builder 6 Examples Bracket and check the Select All Files option IMAQ Vision Builder previews the images in the Preview Image window and displays information about the file format size and type Q Tip The Preview Image window displays all selected images in a sequence To view the images at a different rate adjust the slide to the right of the Preview Image window 4 Click OK to load the image files into IMAQ Vision Builder
42. faces window displays all IMAQ image acquisition boards and channels available for your computer Figure 2 5 shows that two IMAQ hardware boards are available the IMAQ PCI 1408 and the IMAQ PCI 1424 B Note The hardware boards listed in your Interfaces window will vary according to the boards plugged into your computer IMAQ Vision Builder Tutorial 2 8 ni com Chapter 2 Introduction to Image Processing with IMAQ Vision Builder S National Instruments IMAQ Visi C pia StillColor Sequence lt p Number of Frames Skip Count r To r Trigger Line Extemal triggerO _ gt Action Disabled x Timeout f 10000 ms Acquisition module National Instruments IMAQ z Devices i h IMAG PCI 1408 img0 F Channel 0 F Channel 1 F Channel 2 F Channel 3 BH IMAG PCI 1424 mat F Channel 0 v Draw an ROI in the image to acquire only the selected area Click in the image to acquire the full image Help Return 1 Acquisition Window 2 Acquisition Property Page Figure 2 5 3 Store Acquired Image in Browser Button 4 IMAQ Image Acquisition Boards and Channels Acquiring Images in IMAQ Vision Builder The property pages above the Interfaces window list properties available for the selected board In Figure 2 5 the IMAQ PCI 1408 is selected Because the PCI 1408 can acquire a sequence of images you can set the following properti
43. gical functions affect the shape of blobs Each blob or region in the binary image is affected on an individual basis Morphological operations prepare blobs in the image for quantitative analysis such as finding the area perimeter or orientation Use the following steps to apply two morphological functions to the image The first function fills holes in the particles and the second removes objects that touch the border of the Builder image 1 Select Binary Adv Morphology 2 Select Fill holes from the Morphology Advanced function list 3 Click Apply to add this step to the script 4 Select Remove border objects to remove any objects that touch the border of the image as shown in Figure 3 4 5 Click Apply and Close to add this step to the script and close the 7 IMAG Vision Advanced Morphology window File Image Color Grayscale Binary Machine Vision Script Help 2 Sle ulale m 48 B lal el Metal jpg 8 bit 512x512 Mj 4 gt jaje Ti Bay oe PD Script Begin a Filters Convolution Highlight D Threshold Manual Threshold Fi 18 elel Return IMAQ Vision Builder Tutorial 512x512 1 1 Figure 3 4 Modifying Blobs with Morphological Functions 3 8 ni com Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal Isolating Circular Blobs Use the following steps to define a particle filter th
44. hold 1 5 continuous acquisition grabbing images 2 11 conventions used in manual iv creating a LabVIEW VI 3 14 customer education A 1 D documentation conventions used in manual iv IMAQ Vision manuals 1 8 E edge detection 1 6 edge detector 4 6 edges finding in image 4 6 exiting IMAQ Vision Builder 1 2 F features of IMAQ Vision Builder 1 3 fill holes 3 8 filtering 1 5 filtering images 3 5 find circular edge 1 6 find straight edge 1 6 finding edges 4 6 full size view Image Browser 2 2 IMAQ Vision Builder Tutorial l 2 functions binary processing and analysis functions 1 6 calibration functions 1 7 color image processing functions 1 5 grayscale image processing functions 1 5 image analysis functions 1 4 machine vision functions 1 6 morphological functions 3 8 G gauging analyzing results 4 11 batch processing 4 10 bracket specifications figure 4 2 definition 4 1 finding edges 4 6 finding measurement points using pattern matching 4 3 introduction 4 1 loading images 4 3 making measurements 4 7 to 4 9 overview 4 1 getting help 1 7 getting started in IMAQ Vision Builder 2 1 to 2 7 grab 2 7 grabbing images continuous acquisition 2 11 grayscale image processing and analysis functions 1 5 centroid 1 5 quantify 1 5 grayscale morphology 1 5 grid calibration 1 7 ni com H help IMAQ Vision Builder scripts 1 9 IMAQ Vision documentation 1 8 Nati
45. ine Tool from the Tools palette and graphs the result 3D View Displays an image using an isometric view Each pixel from the image source is represented as a column of pixels in the 3D view The pixel value corresponds to the altitude 1 4 ni com Chapter 1 System Requirements and Installation Color Image Processing Functions IMAQ Vision Builder includes a comprehensive set of functions for processing and analyzing color images including the following e Color Operators Applies an arithmetic operation between two images or between an image and a constant e Color Plane Extraction Extracts the Red Green or Blue plane or the Hue Saturation or Luminance plane of a color image e Color Threshold Applies a threshold to the three planes of an RGB or HSL image e Color Location Locates colors in an image e Color Matching Compares the color content of one or multiple regions in an image to a reference color set e Color Pattern Matching Searches for a color template in an image Grayscale Image Processing and Analysis Functions IMAQ Vision Builder also includes functions for grayscale image processing and analysis e Filtering Functions for smoothing edge detection and convolution e Lookup Tables Applies predefined lookup table transformations to the image to modify the dynamic intensity of regions in the image with poor contrast e Operators Performs basic arithmetic and logical operations on images
46. jects from the background by assigning all pixels with intensities within a specified range to the object and the rest of the pixels to the background In the resulting binary image objects are represented with a pixel intensity of 255 and the background is set to 0 Two parameters the lower threshold gray level value and the upper threshold gray level value Tagged Image File Format Image format commonly used for encoding 8 bit 16 bit and color images extension TIF Collection of tools that enable you to select regions of interest zoom in and out and change the image palette G 10 ni com Glossary value The grayscale intensity of a color pixel computed as the average of the maximum and minimum red green and blue values of that pixel VI Virtual Instrument 1 A combination of hardware and or software elements typically used with a PC that has the functionality of a classic stand alone instrument 2 A LabVIEW software module VI which consists of a front panel user interface and a block diagram program National Instruments Corporation G 11 IMAQ Vision Builder Tutorial Index Numerics 3D view 1 4 A acquiring images grab continuous image 2 11 opening the Interface window 2 8 3 2 region of interest 2 11 sequence 2 11 snap single image 2 10 acquisition types grab 2 7 sequence 2 7 snap 2 7 Acquisition window 1 3 opening 2 8 acquisiton modules 2 8 advanced edge tool 4 6 analyzing blob
47. lection of tools from the Lab VIEW Tools palette that enable you to select a region of interest from an image These tools let you select a point or line polygon rectangle and oval regions and freehand lines and areas A pattern matching technique in which the reference pattern can be located at any orientation in the test image as well as rotated at any degree IMAQ Vision Builder Tutorial Glossary S saturation scale invariant matching shift invariant matching smoothing filter sub pixel analysis T template threshold threshold interval TIFF Tools palette IMAQ Vision Builder Tutorial The amount 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 low saturation A pattern matching technique in which the reference pattern can be any size in the test image A pattern matching technique in which the reference pattern can be located anywhere in the test image but cannot be rotated or scaled Blurs an image by attenuating variations of light intensity in the neighborhood of a pixel Finds the location of the edge coordinates in terms of fractions of a pixel Color shape or pattern that you are trying to match in an image using the color matching shape matching or pattern matching functions A template can be a region selected from an image or it can be an entire image Separates ob
48. llow these steps to find the area occupied by them 1 Select Binary Particle Analysis A results table is displayed with all of the measurement results IMAQ Vision Builder assign numerical labels to each blob The first row of the results table lists the numerical label associated with each blob Click the Show Hide Labels button to view the labels Y Tip When you click on a blob the measurement results for that blob are highlighted in blue When you click on the results for a blob the blob is highlighted in green in the processing view Ot Oy OY oe To show only the area measurement click the Choose Measurements button Click None to deselect all of the measurements Click Area unit Click OK Click Apply to record the particle analysis in the script Click Close You now have all of the information you need to analyze the structure of the metal Remember to include the analysis as part of your LabVIEW LabWindows CVI or Visual Basic solution You also can use Microsoft Excel to analyze the data generated by IMAQ Vision Builder Tip To send the data to Microsoft Excel click the Send Data to Excel button in the Particle Analysis results window Testing the Blob Analysis Script The script that you created as you processed this image is a custom algorithm To test this algorithm run it on another image in the collection using the following steps IMAQ Vision Builder Tutorial 1 Click the Image Browser bu
49. nd then finds a line describing the edge Find Circular Edge Locates the intersection points between a set of search lines within a circular area annulus and then finds the best fit circle Clamp Finds edges within a rectangular ROI drawn in the image and measures the distance between the first and last edge Pattern Matching Locates regions of a grayscale image that match a predetermined template Pattern Matching can find template matches regardless of poor lighting blur noise shifting of the template and rotation of the template Caliper Computes measurements such as distances areas and angles based on results returned from other machine vision and image processing functions 1 6 ni com Calibration Functions Chapter 1 System Requirements and Installation IMAQ Vision Builder features several calibration functions including the following Getting Help Simple Calibration Sets a simple calibration for an image This function sets the horizontal and vertical scaling factor as well as the origin and orientation of the coordinate system for the image Grid Calibration Learns a calibration based on the image of a grid template acquired with the imaging setup you are calibrating Calibration from Image Applies the calibration information saved in an image file to the current image Image Correction Transforms a distorted image acquired in a calibrated setup into an image where perspective errors and lens
50. ndow Records a series of image processing steps and the settings you use for each of those steps You can run scripts on single images or image collections batch processing You can modify and save scripts See Figure 2 4 Thresholded Image to view a script in the Script window e Image Browser Contains all of the images currently loaded in IMAQ Vision Builder Through the Image Browser you can select an image to process by double clicking on it See Figure 2 1 Image Browser to view images loaded into the Image Browser e Acquisition window Displays the Interfaces window IMAQ image acquisition boards and channels available and the property pages for the IMAQ image acquisition board See Figure 2 5 Acquiring Images in IMAQ Vision Builder to view all the elements of the Acquisition window National Instruments Corporation 1 3 IMAQ Vision Builder Tutorial Chapter 1 System Requirements and Installation Processing window Updates the image as you change parameters Because this view immediately reflects the changes you have made in the parameters window you can continue modifying parameters until you get the desired result See Figure 2 2 Processing an Image to view an image loaded into the Processing window Parameter window Displays parameters that you can set for an image processing function Each IMAQ Vision function available through the menus has a parameter window in which you set the parameters for that function
51. ndow appears on the left side of the IMAQ Vision Builder window The progress window displays the current process acquiring an image or processing an image the number of times the process has been completed the starting time and an estimation of the time remaining If you ever need to stop a batch process click the Cancel button 3 Note Because you checked Open Results Panel when setting up the batch processing parameters you must click the Done button after the script runs on each image 8 9 When the batch processing completes click OK Click Return to exit the Batch Processing window The bracket images have been processed and the caliper results stored in a text file IMAQ Vision Builder Tutorial 4 10 ni com Chapter 4 Using Gauging for Part Inspection Analyzing the Results As you implement this algorithm in your development environment using the LabVIEW VI creation feature or the Builder file remember to include your analysis For this example you can use Microsoft Excel to quickly analyze the results 3 Note To complete this part of the tutorial you must have Microsoft Excel 97 or higher installed on your computer 1 Launch Microsoft Excel 2 Open bracket txt from within Excel to view the results The results are labeled and listed in the order in which they appear in the Image Browser In this case images are listed from Bracket1 jpg to Bracket6 jpg Table 4 1 lists the acceptable ranges for the
52. nment Help IMAQ Vision Contains reference information about IMAQ Vision VIs e IMAQ Vision for Measurement Studio IMAQ Vision for Measurement Studio User Manual LabWindows CVI Contains information about how to build a vision application using IMAQ Vision for LabWindows CVI IMAQ Vision for LabWindows CVI online help Contains reference information about IMAQ Vision for LabWindows CVI IMAQ Vision for Measurement Studio User Manual Visual Basic Contains information about how to build a Vision application using the tools for Visual Basic that come with IMAQ Vision for Measurement Studio IMAQ Vision for Visual Basic online help Contains reference information about the tools for Visual Basic that come with IMAQ Vision for Measurement Studio For detailed information about the concepts and algorithms used by IMAQ Vision Builder launch the IMAQ Vision Concepts Manual from the Start menu Start Programs National Instruments IMAQ Vision Builder 6 gt IMAQ Vision Concepts Manual National Instruments Web Site IMAQ Vision Builder Tutorial The National Instruments Web site provides information about IMAQ hardware and software Visit the site at ni com imaq From the IMAQ site you can locate information about new IMAQ Vision features machine vision problems and solutions using MMX technology on machine vision applications and selecting the appropriate IMAQ hardware cameras lenses and lighting equipm
53. o understand how IMAQ Vision Builder works and what you can accomplish with IMAQ Vision Builder is by using it In this short example you load images into IMAQ Vision Builder and perform one image processing function a threshold Thresholding isolates objects so that you can keep those that interest you and remove those that do not Thresholding also converts the image from a grayscale image with pixel values ranging from 0 to 255 to a binary image with pixel values of 0 or 1 Follow these steps to get started in IMAQ Vision Builder 1 Launch IMAQ Vision Builder from the Start menu Start Programs National Instruments IMAQ Vision Builder 6 2 To load images select the Open Image button from the Welcome Screen 3 Navigate to Program Files National Instruments IMAQ Vision Builder 6 Examples Metal and check the Select All Files option IMAQ Vision Builder previews the images in the Preview Image window and displays information about the file type and image depth 4 Click OK National Instruments Corporation 2 1 IMAQ Vision Builder Tutorial Chapter 2 Introduction to Image Processing with IMAQ Vision Builder IMAQ Vision Builder loads those image files into the Image Browser as shown in Figure 2 1 The Image Browser provides information about the selected image such as image size location and type MEE File Image Color Grayscale Binary Machine Vision Script Help S wms le ulala mml a X
54. oints click the Zoom In tool in the Tools palette to magnify the image Magnification factors are displayed in the lower left corner of the processing window 1 1 specifies 100 magnification default 2 1 specifies a slightly magnified view and 1 2 specifies a slightly demagnified view Tip Instead of clicking on the points in the image you can double click on the points in the Points list box to select them When you select a point IMAQ Vision Builder places a check mark next to it ug 3 Select Center from the Type of Measure list National Instruments Corporation 4 7 IMAQ Vision Builder Tutorial Chapter 4 Using Gauging for Part Inspection 4 Click the Measure button to compute the center of the bracket s width and add the Width Center measurement to the results table as shown in Figure 4 6 National Instruments File Image Color Grayscale Binay Machine Vision Script Help el s siz E 20 Toler 2 2 Begin Pattern Matching Pattern Matching 2 Pattern Matching Select 2 points 3 Edge Detector or more 4 Edge Detector Figure 4 6 Using the Caliper Function to Find Width Center Click Apply to add this step to the script Select Machine Vision Caliper again The center of the bracket s width appears as point 5 7 Click on points 1 and 2 in the image to find the second measurement Bracket Distance which measures the length between the manufactured hol
55. on 3 5 IMAQ Vision Builder Tutorial Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal National Instruments IMAQ Vision i 3 Se ae Machine Vis Builder Peta e Lie gt mile S Aolo K Gray Levels 512x512 1 1 fig Line Profile Mapping mode k Linear Logarithmic Minimum Value 22 00 Maximum Value 235 00 Mean Value 151 62 Help Std Deviation 73 41 R Number of Pixels 68 Close elel T a Return Figure 3 2 Using a Line Profile to Examine Particle Edges Separating Particles from the Background with Thresholding Thresholding isolates pixels that interest you and sets the remaining pixels as background pixels Thresholding also converts the image from grayscale to binary The Threshold parameter window displays a histogram A histogram counts the total number of pixels in each grayscale value and graphs it From the graph you can tell whether the image contains distinct regions of a certain grayscale value and you can select pixel regions of the image Follow these steps to select a range of brighter pixels to analyze 1 Select Grayscale Threshold 2 Select Manual Threshold from the Threshold list IMAQ Vision Builder Tutorial 3 6 ni com Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal 3 Select a range of 130 to 255 Notice that the particles of interest circular
56. onal Instruments Web site 1 8 online help 1 7 Heywood Circularity Factor particle filter 3 9 histogram 1 4 2 4 3 6 in Threshold parameter window 2 4 l image acquisition 2 7 image acquisition See acquiring images image analysis functions 1 4 3D view 1 4 histogram 1 4 line profile 1 4 Image Browser accessing from the toolbar 3 11 definition 1 3 full size view 2 2 important elements figure 2 2 thumbnail view 2 2 image correction 1 7 image processing entering processing mode 2 3 getting started in IMAQ Vision Builder 2 1 to 2 7 thresholding images 2 5 images loading for blob analysis 2 3 for gauging 4 3 for image processing 2 3 opening in IMAQ Vision Builder 2 1 IMAQ hardware 1 1 2 7 National Instruments Corporation l 3 Index IMAQ Vision Builder acquiring images 2 7 to 2 12 binary processing and analysis functions 1 6 calibration functions 1 7 color image processing functions 1 5 environment 1 3 exiting 1 2 features 1 3 getting help 1 7 getting started 2 1 to 2 7 grayscale image processing and analysis functions 1 5 image analysis functions 1 4 installing 1 2 using with LabVIEW 3 10 using with LabWindows CVI 3 10 launching 1 2 machine vision functions 1 6 online help 1 7 sending data to Microsoft Excel 4 11 system requirements 1 1 using with Microsoft Excel 3 10 using with Visual Basic 3 10 IMAQ Vision documentation 1 8 installing IMAQ Vision Builder 1 2 Inte
57. plate from the same region of the image Click Apply to add this step to the script With the Rectangle Tool draw a region of interest around the right side of the bracket as shown in Figure 4 4 IMAQ Vision Builder automatically locates the template in the region bound by the rectangle and displays the score and location of the match Figure 4 4 Selecting the Second Search Area The score of the second match is not a perfect 1000 but it is high enough for you to consider it a match to the template Click Apply to add this step to the script Click Close 4 5 IMAQ Vision Builder Tutorial Chapter 4 Using Gauging for Part Inspection Finding Edges in the Image Before you can compute measurements to determine whether a bracket meets specifications you need to detect edges on which you can base the measurements The Edge Detector function finds edges along a line that you draw with the Line Tool from the Tools palette 1 Select Machine Vision Edge Detector 2 Select the Advanced Edge Tool The Advanced Edge Tool is effective on images with poor contrast between the background and objects 3 Select First amp Last Edge so that IMAQ Vision Builder finds and labels only the first and last edges along the line you draw 4 Set the Contrast to 40 The detection process only returns the first and last edge whose contrast is greater than 40 5 Click and drag to draw a vertical line across the middle of the bracket to find th
58. r prototyping a blob analysis application in IMAQ Vision Builder What Is Blob Analysis Blob analysis consists of a series of processing operations and analysis functions to produce some information about the blobs in an image A blob binary large object is defined as a connected region or grouping of pixels in an image in which all pixels have the same intensity level In a binary image the background pixels are zero and every non zero pixel is part of a binary object You perform a blob analysis to find statistical information such as the size of the blobs or the number location and presence of blob regions With this information you can detect flaws on silicon wafers detect soldering defects on electronic boards or locate objects in motion control applications when there is significant variance in part shape or orientation Tutorial In this tutorial you find the area of circular particles in a metal As you perform this analysis IMAQ Vision Builder records all of the processing operations and parameters in a script You will run that script on other images to test your blob analysis algorithm To find the total area of circular particles you will perform the following image processing steps e Filter the image to sharpen edges and ease the separation of the particles from the background e Threshold the image to isolate pixels that interest you the particles e Fill holes that appear in the particles after thr
59. rement Points Using Pattern Matching eee eee eens 4 3 Finding Edges in the Image cinarios 4 6 Taking the Measurements onesie e e EE Ea 4 7 Analyzing a Collection of Images with Batch Processing 0 0 00 4 10 Analyzing the Results s Poes r EEA ara E a eaa EE inas 4 11 Appendix A Technical Support Resources Glossary Index IMAQ Vision Builder Tutorial vi ni com System Requirements and Installation This chapter lists system requirements and installation instructions and introduces the IMAQ Vision Builder environment System Requirements To run IMAQ Vision Builder you must have the following minimum system requirements e Personal computer using at least a 133 MHz Pentium or higher microprocessor 233 MHz Pentium MMX or higher microprocessor recommended e Microsoft Windows 2000 NT Me 9x If you are using Windows NT 4 0 you must have Service Pack 3 or higher installed on your computer to run IMAQ Vision Builder e 800 x 600 resolution or higher video adapter 65 536 colors 16 bit or higher e National Instruments image acquisition IMAQ hardware and NI IMAQ 2 5 or higher for Windows 2000 NT Me 9x if you are acquiring images e Minimum of 32 MB RAM 64 MB recommended e Minimum of 40 MB of free hard disk space 3 Note You need Microsoft Excel 97 or higher installed on your computer to complete a few steps in the second tutorial National Instruments Corporation 1 1 IMAQ Vision Builder Tutorial
60. rface window acquisition 1 3 Interfaces window 2 8 invert binary image 1 6 isolating circuar blobs 3 9 L LabVIEW 3 10 LabVIEW VI creation 1 4 4 11 LabVIEW VI creation wizard 3 14 LabWindows CVI 3 10 launching IMAQ Vision Builder 1 2 line profile 1 4 3 3 4 6 line tool 3 3 IMAQ Vision Builder Tutorial Index loading images blob analysis 3 2 gauging 4 3 image processing 2 3 lookup tables 1 5 machine vision functions 1 6 caliper 1 6 clamp 1 6 edge detection 1 6 find circular edge 1 6 find straight edge 1 6 pattern matching 1 6 magnifying an image 4 7 manuals for IMAQ Vision 1 8 Measurement amp Automation Explorer MAX 2 7 measurements for gauging See gauging Microsoft Excel using with IMAQ Vision Builder 3 10 4 11 morphology 3 8 National Instruments Web site 1 8 National Instruments Web support A 1 NI Developer Zone A 1 NI IMAQ 1 1 2 7 0 online help 1 7 opening images 2 1 3 2 4 3 operators 1 5 P Parameter window 1 4 part inspection 4 1 IMAQ Vision Builder Tutorial particle analysis 1 6 3 10 particle filter 3 9 particle filtering 1 6 particles separating from background with thresholding 3 6 pattern matching 1 6 pattern matching for finding measurement points 4 3 Performance Meter 1 4 3 13 Preview Image window 3 2 4 3 processing mode 2 3 Processing window 1 4 2 3 Q quantify 1 5 R Reference window definition
61. rials 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 period National Instruments does not warrant that the operation of the software shall be uninterrupted or error free A Return Material Authorization RMA number must be obtained from the factory and clearly marked on the outside of the package before any equipment will be accepted for warranty work National Instruments will pay the shipping costs of returning to the owner parts which are covered by warranty National Instruments believes that the information in this document is accurate The document has been carefully reviewed for technical accuracy In the event that technical or typographical errors exist National Instruments reserves the right to make changes to subsequent editions of this document without prior notice to holders of this edition The reader should consult National Instruments if errors are suspected In no event shall National Instruments be liable for any damages arising out of or related to this document or the information contained in it EXCEPT AS SPECIFIED HEREIN NATIONAL INSTRUMENTS MAKES NO WARRANTIES EXPRESS OR IMPLIED AND SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURP
62. rporation 2 3 IMAQ Vision Builder Tutorial Chapter 2 Introduction to Image Processing with IMAQ Vision Builder 7 Select Grayscale Threshold The Threshold parameter window appears in the lower right corner of the IMAQ Vision Builder window as shown in Figure 2 3 f National Instruments File Image Calo Binan Machine Vision Script Help vme se uja BB OMANE oo E ojoloje sf GreyLevels HAEE Toler e alam B Script El 512x512 1 1 Threshold Image Source x Auto Threshold Clustering Auto Threshold Entropy Return Auto Threshold Metric 1 Tools Palette 2 Threshold Parameter Window Figure 2 3 Thresholding an Image The Threshold parameter window displays a histogram A histogram counts the total number of pixels at each grayscale value and graphs it From the graph you can tell whether the image contains distinct regions of a certain grayscale value and you can select pixel regions of the image For example if the background of an image is black and you want to remove it you can select a range with values close to 255 white IMAQ Vision Builder Tutorial 2 4 ni com wg Chapter 2 Introduction to Image Processing with IMAQ Vision Builder The Processing window displays a preview of the threshold operation using the current set of parameters The pixels depicted in red have intensities that fall inside the threshold range The threshold
63. s G 2 ni com C caliper chroma chrominance circle function closing color images contrast convolution kernel D default setting definition digital image dilation driver National Instruments Corporation G 3 Glossary 1 A function in IMAQ Vision Builder that calculates distances angles circular fits and the center of mass based on positions given by edge detection particle analysis centroid and search functions 2 A measurement function that finds edge pairs along a specified path in the image This function performs an edge extraction and then finds edge pairs based on specified criteria such as the distance between the leading and trailing edges edge contrasts and so forth The color information in a video signal See chroma Detects circular objects in a binary image A dilation followed by an erosion A closing fills small holes in objects and smooths the boundaries of objects Images containing color information usually encoded in the RGB form A constant multiplication factor applied to the luma and chroma components of a color pixel in the color decoding process 2D matrices or templates used to represent the filter in the filtering process The contents of these kernels are a discrete two dimensional representation of the impulse response of the filter that they represent A default parameter value recorded in the driver In many cases the default input of a control is a
64. s 3 10 batch processing 1 3 4 10 binary morphology 1 6 binary processing and analysis functions 1 6 circle detection 1 6 invert binary image 1 6 particle analysis 1 6 blob 3 1 blob analysis analyzing circular blobs 3 10 definition 3 1 estimating processing time 3 13 examining image 3 3 filtering 3 5 introduction 3 1 National Instruments Corporation isolating circular blobs 3 9 modifying blobs with morphological functions 3 8 morphology 3 8 opening images 3 2 overview 3 1 particle analysis 3 10 particle filter 3 9 preparing images for processing 3 2 to 3 5 saving the script 3 13 separating particles from background 3 6 testing the script 3 10 thresholding 3 6 Browser See Image Browser Builder file 4 11 C calibration from image 1 7 calibration functions 1 7 calibration from image 1 7 grid calibration 1 7 image correction 1 7 simple calibration 1 7 caliper 1 6 4 7 to 4 9 centroid 1 5 Choose Measurements button 3 10 circle detection 1 6 circular blobs analyzing 3 10 isolating 3 9 clamp 1 6 closing IMAQ Vision Builder 1 2 color image processing functions 1 5 color location 1 5 color matching 1 5 color operators 1 5 IMAQ Vision Builder Tutorial Index color pattern matching 1 5 color plane extraction 1 5 color threshold 1 5 color location 1 5 color matching 1 5 color operators 1 5 color pattern matching 1 5 color plane extraction 1 5 color thres
65. s according to settings that you specify and sends the images to the Image Browser If you have National Instruments IMAQ image acquisition boards and NI IMAQ 2 5 or later installed on your computer you can acquire live images in IMAQ Vision Builder For more information on setting up your boards and channels in Measurement amp Automation Explorer MAX see the MAX online help If you do not have IMAQ image acquisition boards and NI IMAQ 2 5 or later installed on your computer IMAQ Vision Builder automatically simulates the acquisition process by displaying a sequence of images You can stop the sequence at any frame capture the image and send the image to the Image Browser for processing National Instruments Corporation 2 7 IMAQ Vision Builder Tutorial Chapter 2 Introduction to Image Processing with IMAQ Vision Builder Opening the Acquisition Window If IMAQ Vision Builder is not loaded launch the application from the Start menu Start Programs National Instruments IMAQ Vision Builder 6 Click the Acquire Image button from the Welcome Screen to view the Acquisition window as shown in Figure 2 5 If you already have IMAQ Vision Builder running click the Acquire Image button in the toolbar IMAQ Vision Builder displays the Acquisition window as shown in Figure 2 5 The acquisition plug in list shows the different modules that you can use to acquire images e Simulation module e Image acquisition board The Inter
66. s menu items and dialog box options Bold text also denotes parameter names Italic text denotes variables emphasis a cross reference or an introduction to a key concept This font also denotes text that is a placeholder for a word or value that you must supply Text in this font denotes text or characters that you should enter from the keyboard sections of code programming examples and syntax examples This font is also used for the proper names of disk drives paths directories programs subprograms subroutines device names functions operations variables filenames and extensions and code excerpts Contents Chapter 1 System Requirements and Installation System REQUITEMICHIS vesse peers esegi aei deaa dae er e EE S 1 1 Installing IMAQ Vision Builder oo eee ceeceesceesecesseceseeececeaeeeseeeeecsseeesaeseaeessaeeeaeenses 1 2 Launching and Exiting IMAQ Vision Builder 00 cece eecceesceeeeeeeeeeeseeeneeeeaeceeeeneeeeaes 1 2 IMAQ Vision Builder Environment cccccccceessecesseceeseeessseceessneeecseeeesseeeesseeesenees 1 3 CATR eS cscs sted E EEPE EEE EEE EIE E E 1 3 Image Analysis Functions sssssnenncienariios te ei i e i r 1 4 Color Image Processing Functions sseeesseseesssrserssesreresrrersresrrsrsresesresresene 1 5 Grayscale Image Processing and Analysis Functions sseseeeeseeeeeesreersreeeeee 1 5 Binary Processing and Analysis Functions 0 0 ecceeeseeseeeeeseeeeeeseeeeeeneesees 1 6 Ma
67. s the active image with the open script The Performance Meter gives both an estimate of the total time IMAQ Vision will take to process the image and an estimate of the time each function within the script will require Follow these steps to estimate how many milliseconds IMAQ Vision will use to process Metal3 jpg with blob analysis scr 1 Select Script gt Performance Meter The Performance Meter gives an estimate of the total time IMAQ Vision will take to run the script 2 Click Details to view an itemized list of the time IMAQ Vision will take to perform each function in the script 3 Click OK to close the Performance Meter National Instruments Corporation 3 13 IMAQ Vision Builder Tutorial Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal Creating a LabVIEW VI 1 Threshold Narai Theerhold Ate Mophdoz Aenove badk Ade Nowphology Fahle Patches Fler Pathe insys Erd Si LabVIEW I Creation Wizard Step 1 lt Back Next gt Figure 3 8 LabVIEW VI Creation Wizard IMAQ Vision Builder features a wizard that creates the LabVIEW and IMAQ Vision VI for implementing the different steps of your script Figure 3 8 shows the VI creation wizard Select the IMAQ Vision Builder script Current Script Script Saved on Disk Script Path Finish Cancel Follow these steps to create your LabVIEW VI Select Script Create LabVIEW VI 3 Note If several versions of LabVIEW and
68. s the essential resource for building measurement and automation systems At the NI Developer Zone you can easily access the latest example programs system configurators tutorials technical news as well as a community of developers ready to share their own techniques Customer Education National Instruments provides a number of alternatives to satisfy your training needs from self paced tutorials videos and interactive CDs to instructor led hands on courses at locations around the world Visit the Customer Education section of ni com for online course schedules syllabi training centers and class registration System Integration If you have time constraints limited in house technical resources or other dilemmas you may prefer to employ consulting or system integration services You can rely on the expertise available through our worldwide network of Alliance Program members To find out more about our Alliance system integration solutions visit the System Integration section of ni com National Instruments Corporation A 1 IMAQ Vision Builder Tutorial Appendix A Worldwide Support National Instruments has offices located around the world to help address your support needs You can access our branch office Web sites from the Worldwide Offices section of ni com Branch office Web sites provide up to date contact information support phone numbers e mail addresses and current events If you have searched the
69. tion invariant matching National Instruments Corporation G 9 Glossary The ratio between the physical horizontal size and the vertical size of the region covered by the pixel An acquired pixel should optimally be square thus the optimal value is 1 0 but typically it falls between 0 95 and 1 05 depending on camera quality The number of bits used to represent the gray level of a pixel Portable Network Graphic Image file format for storing 8 bit 16 bit and color images with lossless compression extension PNG A finite combination of successive closing and opening operations that you can use to fill small holes and smooth the boundaries of objects A finite combination of successive opening and closing operations that you can use to remove small particles and smooth the boundaries of objects Points Obtaining various measurements of objects in an image The number of rows and columns of pixels An image composed of m rows and n columns has a resolution of mxn Color encoding scheme using red green and blue RGB color information where each pixel in the color image is encoded using 32 bits 8 bits for red 8 bits for green 8 bits for blue and 8 bits for the alpha value unused Region of interest 1 An area of the image that is graphically selected from a window displaying the image This area can be used focus further processing 2 A hardware programmable rectangular portion of the acquisition window Col
70. tton in the Standard toolbar 2 Double click the third image Metal3 jpg 3 10 ni com ag Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal Tip Rather than returning to the Image Browser you can navigate through the images in the Image Browser from the Reference window Click the Next Image and Previous Image buttons until you see the image you want to process and then click the Make Image Active button to move that image into the Processing window 3 Click the Run Script button Figure 3 6a shows the original image Metal3 jpg Figure 3 6b shows the image after the blob analysis processing Notice that two circular blobs are removed from the image during processing because they are touching each other Adjust the thresholding step to separate particles from each other Ey 1 Overlapping Circular Blobs Figure 3 6 Comparing the Original Image to the Processed Image 4 Click Done to close the Particle Analysis window Double click the Threshold step in the script window to open the threshold parameters Figure 3 7 shows Metal3 jpg at the thresholding step of the script National Instruments Corporation 3 11 IMAQ Vision Builder Tutorial Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal National Instruments File Image Color Grayscale Binay Machine Vision Script Help Be S vme B S ulala Alma aea e Metala jog 8 bit 512x512 eee
71. ucture of objects in an image You can use these transformations for expanding dilating or reducing eroding objects filling holes closing inclusions or smoothing borders They are used primarily to delineate objects and prepare them for quantitative inspection analysis A pixel whose value affects the value of a nearby pixel when an image is processed The neighbors of a pixel are usually defined by a kernel or a structuring element Operations on a point in an image that take into consideration the values of the pixels neighboring that point Driver software for National Instruments IMAQ hardware An erosion followed by a dilation An opening removes small objects and smooths boundaries of objects in the image Allow masking combination and comparison of images You can use arithmetic and logic operators in IMAQ Vision The gradation of colors used to display an image on screen usually defined by a color lookup table The technique used to locate quickly a grayscale template within a grayscale image An element of a digital image Also called pixel Picture element The smallest division that makes up the video scan line For display on a computer monitor a pixel s optimum dimension is square aspect ratio of 1 1 or the width equal to the height G 8 ni com pixel aspect ratio pixel depth PNG proper closing proper opening pts Q quantitative analysis R resolution RGB ROI ROI tools rota
72. ure of a Metal National Instruments IMAQ Vision Fil Image Color Grayscale Binary Machine Vision Script Help C Didar vmo se ulo am ie gt a mite ls Cy D A 20 Toler PJA alam By Script E 512x512 1 1 T Line Profile Mapping mode s Linear Minimum Value 31 00 y Logarithmic Maximum Value 225 00 Mean Value 149 31 Hep Std Deviation 63 73 aa A Number of Pixels 68 El Close BIB e s Reun ee 1 Edges of Particles 3 Segment Drawn with Line Tool 2 Fluctuation in Pixel Values Figure 3 1 Using a Line Profile to Examine Edges In Figure 3 1 the areas labeled 1 represent the edges of the particles Notice that the edges of both particles have a slope The more shallow the slope the greater variation you will have in detecting the exact location of the edge As you change the threshold level in images with shallow sloped particle edges you could inadvertently change the shape or size of the particle In the Filtering the Image section you use the Convolution Highlight Details filter under Grayscale Filters to define the edges of the particles and increase the slope IMAQ Vision Builder Tutorial 3 4 ni com Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal The area labeled 2 is a fluctuation in pixel values which may be caused by brighter and darker pixels in the center of the parti
73. y open parameter windows Save your script and images if you want to keep them Select File Exit 1 2 ni com Chapter 1 System Requirements and Installation IMAQ Vision Builder Environment IMAQ Vision Builder is a tool for prototyping and testing image processing applications To prototype your image processing application you build custom algorithms with the IMAQ Vision Builder scripting feature The scripting feature records every step of your processing algorithm After completing the algorithm you can test it on other images to make sure it works The algorithm is recorded in a Builder file Builder files are ASCII text files that list the processing functions and relevant parameters for an algorithm that you prototype in IMAQ Vision Builder Using the LabVIEW VI creation wizard you can create a LabVIEW VI that performs the prototype that you created in IMAQ Vision Builder ays Note You must have LabVIEW 6 0 or higher and IMAQ Vision 6 for LabVIEW or higher installed on your machine to use this feature Features For more information on LabVIEW VI creation see Creating a LabVIEW VI in Chapter 3 Using Blob Analysis to Analyze the Structure of a Metal You can also implement the algorithm defined by the Builder file into any development environment such as LabWindows CVI or Visual Basic using the IMAQ Vision machine vision and image processing libraries IMAQ Vision Builder offers the following features e Script wi

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