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IMAQ ™ IMAQ Vision for Measurement Studio ™ User Manual LabWindows/CVI IMAQ Vision for Lab Windows/CVI User Manual May 2001 Edition Part Number 323022 A-01.
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Conventions The follo wing con ventions 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, selec t the Pa ge Setup item, and select Options from the last dialog box.
© National Instruments Cor poration v IMAQ Vision for LabWindows/CVI User Manu al Contents Chapter 1 Introduction to IMAQ Vision About IMAQ Vision ....... .......................... ...................... .......................... ..................
Contents IMAQ Vision for LabWindows/CVI User Manual vi ni.com Measure Color Statistics ...................... .......................... ......................... ....................... 3-7 Comparing Colors ............ .............. ...............
Contents © National Instruments Cor poration vii IMAQ Vision for LabWindows/CVI User Manu al Training the Color Pattern Matching Algorithm ............. .................. 5-20 Defining a Search Area .............. ......................... .........
© National Instruments Corporation 1-1 IMAQ Vision for LabWindows/CVI User Manual 1 Introduction to IMAQ Vision This chapter describes the IMAQ Vision for LabWindows/CVI software and associated softw.
Chapter 1 Introduction to IMAQ Vision IMAQ Vision for LabWindows/CVI User Manual 1-2 ni.com Documentation » IMA Q V ision for LabW indows/CVI Function Refere nce . • Example programs — If you want examples of ho w to create specific applications, go to cvisamplesvision .
Chapter 1 Introduction to IMAQ Vision © National Instruments Corporation 1-3 IMAQ Vision for LabWindows/CVI User Manual Table 1-1. IMAQ Vision Function T ypes Function T ype Description Image Management Functions that create space in memory for images and perform basic image manipulation.
Chapter 1 Introduction to IMAQ Vision IMAQ Vision for LabWindows/CVI User Manual 1-4 ni.com IMAQ Machine Vision Function T ree The IMAQ Machine Vision function tree ( NIMachineVision.fp ) contains separate classes c orresponding to grou ps or types of function s.
Chapter 1 Introduction to IMAQ Vision © National Instruments Corporation 1-5 IMAQ Vision for LabWindows/CVI User Manual Creating IMAQ Vision Applications Figures 1-1 and 1-2 illustrate the steps for creating an applicatio n with IMAQ Vision. Figure 1-1 describ es the general steps to designing a Visi on application.
Chapter 1 Introduction to IMAQ Vision IMAQ Vision for LabWindows/CVI User Manual 1-6 ni.com Figure 1-2. Inspection Steps for Building a Vision Application Define Regions of Interest Chapter 3: Graysca.
© National Instruments Corporation 2-1 IMAQ Vision for LabWindows/CVI User Manual 2 Getting Measurement-Ready Images This chapter describes how to set up your imaging system, acquire and display an image, analyze the image, and prepare the im age for additional processing.
Chapter 2 Getting Measurement-Ready Images IMAQ Vision for LabWindows/CVI User Manual 2-2 ni.com 3. Select an image acquisition de vice that meets your needs. National Instruments offers se veral image acquisition (IMA Q) devices, such as analog color and monochrome IMA Q de vices as well as digital de vices.
Chapter 2 Getting Measurement-Ready Images © National Instruments Corporation 2-3 IMAQ Vision for LabWindows/CVI User Manual If you plan to use filtering or blob analysis f unctions on the image, s et the appropriate border size for th e image. The default border size is 3.
Chapter 2 Getting Measurement-Ready Images IMAQ Vision for LabWindows/CVI User Manual 2-4 ni.com Source and Destination Images Some IMAQ Vision fun ctions that modify the cont ents of an image have source image and destination image input parameters. The source image receives the image to process.
Chapter 2 Getting Measurement-Ready Images © National Instruments Corporation 2-5 IMAQ Vision for LabWindows/CVI User Manual • imaqAdd(myImageA, myImageA, myImageB); This function adds two source images and stores the result in the first source image.
Chapter 2 Getting Measurement-Ready Images IMAQ Vision for LabWindows/CVI User Manual 2-6 ni.com Acquiring an Image Use one of the foll owing methods to acquire im ages with a National Instruments im age acquisition (IMAQ) d evice: • Acquire a single image using imaqEasyAcquire() .
Chapter 2 Getting Measurement-Ready Images © National Instruments Corporation 2-7 IMAQ Vision for LabWindows/CVI User Manual Use imaqReadVisionFile() to open an image file containing additional information, such as calibration i nformation, template inf ormation for pattern matching, or overlay information.
Chapter 2 Getting Measurement-Ready Images IMAQ Vision for LabWindows/CVI User Manual 2-8 ni.com Attach Calibration Information If you want to attach the calibr ation information of th e current setup to each image you acquire, use imaqCopyCalibrationInfo() .
Chapter 2 Getting Measurement-Ready Images © National Instruments Corporation 2-9 IMAQ Vision for LabWindows/CVI User Manual this range in processing functions, such as determining a threshold ran ge during blob an alysis. If the image quality does not meet you r needs, try to improv e the imaging conditions to get the desi red image quality .
Chapter 2 Getting Measurement-Ready Images IMAQ Vision for LabWindows/CVI User Manual 2-10 ni.com transformations. For more information about these lookup tables, see Chapter 5, Image Processing ,i nt h e IMAQ Visi on Concepts Manual .
Chapter 2 Getting Measurement-Ready Images © National Instruments Corporation 2-11 IMAQ Vision for LabWindows/CVI User Manual Nth Order Filter The imaqNthOrderFilter() function allows you to define a lowpass or highpass filter depending on the val ue of N that you choose.
Chapter 2 Getting Measurement-Ready Images IMAQ Vision for LabWindows/CVI User Manual 2-12 ni.com An image can hav e extraneous noise, such as periodic stripes, introduced during the digitization process. In the frequency domain, the periodic pattern is reduced to a limited set of high spatial fr equencies.
Chapter 2 Getting Measurement-Ready Images © National Instruments Corporation 2-13 IMAQ Vision for LabWindows/CVI User Manual 3. T o transform yo ur image back to the spatial domain, use imaqInverseFFT() .
© National Instruments Corporation 3-1 IMAQ Vision for LabWindows/CVI User Manual 3 Grayscale and Color Measurements This chapter describes how to take measurements from grayscale a nd color images. You can make inspection decisions based on image statistics, such as the mean intensity level in a region.
Chapter 3 Grayscale and Color Mea surements IMAQ Vision for LabWindows/CVI User Manual 3-2 ni.com Table 3-1. T ools Palette Functions Icon To o l N a m e Function Selection T ool Select an R OI in the image an d adjust the position of its co ntrol points and contours.
Chapter 3 Grayscale and Color Measurements © National Instruments Corporation 3-3 IMAQ Vision for LabWindows/CVI User Manual Hold down <Shift> while dra w ing an R OI if you want to constrain the R OI to the horizontal, vertical, or diagonal axes when pos s ible.
Chapter 3 Grayscale and Color Mea surements IMAQ Vision for LabWindows/CVI User Manual 3-4 ni.com Figure 3-2. ROI Constructor 2. Select an R OI tool from the tools palette. 3. Draw an R OI on your image. Resize and reposition the R OI unti l it designates the area you want to inspect.
Chapter 3 Grayscale and Color Measurements © National Instruments Corporation 3-5 IMAQ Vision for LabWindows/CVI User Manual Figure 3-3. T ools Palette T ools and Information The following list describes ho w you can display the tools palette in a separate window and manipulate the palette.
Chapter 3 Grayscale and Color Mea surements IMAQ Vision for LabWindows/CVI User Manual 3-6 ni.com Y ou can also use imaqSelectPoint() , imaqSelectLine() , imaqSelectRect() ,a n d imaqSele ctAnnulus() to define regions of interest. Follo w these steps to use these functions: 1.
Chapter 3 Grayscale and Color Measurements © National Instruments Corporation 3-7 IMAQ Vision for LabWindows/CVI User Manual When you need to make intensity measurements on particles in an image, you can use a mask to define the particles. First, threshold your image to make a new binary image.
Chapter 3 Grayscale and Color Mea surements IMAQ Vision for LabWindows/CVI User Manual 3-8 ni.com image. Using imaqReplaceColorPlanes() , you can reassemble a color image from a set of three 8-bit images, where each image becomes one of the three primary components.
Chapter 3 Grayscale and Color Measurements © National Instruments Corporation 3-9 IMAQ Vision for LabWindows/CVI User Manual 2. Use the entire image or regions in the image to learn the color information using imaqLearnColor() , which outputs a color spectrum that contains a compact description of the color information that you learned.
Chapter 3 Grayscale and Color Mea surements IMAQ Vision for LabWindows/CVI User Manual 3-10 ni.com Figur e 3-5. T emplate Color Information Specifying the Color Information to Learn You can learn the color information associated with an entire image, a region in an image, or multiple regions in an image.
Chapter 3 Grayscale and Color Measurements © National Instruments Corporation 3-11 IMAQ Vision for LabWindows/CVI User Manual Figure 3-7. Using a Single Region to Learn Color Distribution Using Multiple Regions in the Image The interaction of light with an object ’ s surface creates the observed color of that object.
Chapter 3 Grayscale and Color Mea surements IMAQ Vision for LabWindows/CVI User Manual 3-12 ni.com Figure 3-8. Using Multiple Regions to Learn Color Distribution Choosing a Color Representation Sensitivity When you learn a color, you need to specify the sensitivity required to specify the color information.
Chapter 3 Grayscale and Color Measurements © National Instruments Corporation 3-13 IMAQ Vision for LabWindows/CVI User Manual Ignoring Learned Colors Ignore certain color components in color m atching by replacing the corresponding componen t in the input color spectrum array to – 1.
© National Instruments Corporation 4-1 IMAQ Vision for LabWindows/CVI User Manual 4 Blob Analysis This chapter describes how to perform blob (Binary Large Object) analysis on your images. Use blob analy sis to find statistical informatio n about blobs, such as the presence, size, number, and location of blob regions.
Chapter 4 Blob Analysis IMAQ Vision for LabWindows/CVI User Manual 4-2 ni.com Correct Image Distortion If you need to make accurate shape measurements based on the blobs i n an image containing perspective and nonlinear distortion errors, correct the distortion usi ng the calibration inform ation you attached to your image.
Chapter 4 Blob Analysis © National Instruments Corporation 4-3 IMAQ Vision for LabWindows/CVI User Manual Improve the Binar y Image After you threshold your image, you m ay want to improve the resulting binary image with bin ary morphology.
Chapter 4 Blob Analysis IMAQ Vision for LabWindows/CVI User Manual 4-4 ni.com If you know enough about the shape features of the blobs you want to keep, use imaqParticleFilter() to f ilter out parti cles that do not interest you.
Chapter 4 Blob Analysis © National Instruments Corporation 4-5 IMAQ Vision for LabWindows/CVI User Manual commonly used measurements, including the area, projection along the x-axis and y-axis, and perimeter of each blob .
Chapter 4 Blob Analysis IMAQ Vision for LabWindows/CVI User Manual 4-6 ni.com IMAQ_MAX_SEGMENT_LEFT_COLUMN leftmost x-coordinate of longest horizontal lin e segment in a particle IMAQ_MAX_SEGMENT_TOP_.
Chapter 4 Blob Analysis © National Instruments Corporation 4-7 IMAQ Vision for LabWindows/CVI User Manual Convert Pixel Coordinates to Real-W orld Coordinates If you need to find the location of the center of mass o r the bounding rectangle of the blobs in real-world units, use imaqTransformPixelToRealWorld() .
© National Instruments Corporation 5-1 IMAQ Vision for LabWindows/CVI User Manual 5 Machine Vision This chapter describes how to perform many common machine vision inspection tasks. The most common inspection tasks are detecting the presence or absence of parts in an image and measuring the dimensions of parts to see if they meet specifications.
Chapter 5 Machine Vision IMAQ Vision for LabWindows/CVI User Manual 5-2 ni.com Figure 5-1 illustrates the basic steps involved in perfor ming machine vision.
Chapter 5 Machine Vision © National Instruments Corporation 5-3 IMAQ Vision for LabWindows/CVI User Manual appears shifted and rotated in the image you need to process.
Chapter 5 Machine Vision IMAQ Vision for LabWindows/CVI User Manual 5-4 ni.com Figure 5-2. Coordinate Systems of a Reference Image and Inspection Image b. I f y o u u s e imaqFindTransformRects() , specify two rectangles, each containing one separate, s traight boundary of the object, as shown in Figure 5-3.
Chapter 5 Machine Vision © National Instruments Corporation 5-5 IMAQ Vision for LabWindows/CVI User Manual Figure 5-3. Locating Coordinat e S ystem Axes with T wo Search Area s 2.
Chapter 5 Machine Vision IMAQ Vision for LabWindows/CVI User Manual 5-6 ni.com 1. Defi ne a template that represents the part of the object that you want to use as a reference feature. For more information about def ining a template, see the Find Measurement Points section.
Chapter 5 Machine Vision © National Instruments Corporation 5-7 IMAQ Vision for LabWindows/CVI User Manual C h o o s i n gaM e t h o dt oB u i l dt h eC o o r d i n a t eT r a n s f o r m The following flowchart guides you thro ugh choosing the best method for building a coordinate t ransform for your application .
Chapter 5 Machine Vision IMAQ Vision for LabWindows/CVI User Manual 5-8 ni.com Set Search Areas Select regions of interest ( ROIs) in your images to lim it the areas in which you perform your processin g and inspection. You can defin e ROIs interactively or programmatically.
Chapter 5 Machine Vision © National Instruments Corporation 5-9 IMAQ Vision for LabWindows/CVI User Manual Programmatically Defining Regions When you have an automated application, you need to define regions of interest programmatically. You can programmatically define regions in two ways: • Specify the contours of the R OI.
Chapter 5 Machine Vision IMAQ Vision for LabWindows/CVI User Manual 5-10 ni.com Figure 5-5. Finding a Straight Feature 1 Search Region 2S e a r c h L i n e s 3 Detecte d Edge Points 4 Line Fit to Edge.
Chapter 5 Machine Vision © National Instruments Corporation 5-11 IMAQ Vision for LabWindows/CVI User Manual If you w ant to find poi nts along a circular e dge and find t he circle that best fits the edge, as sho wn in Figure 5-6, u se imaqFindCircularEdge() .
Chapter 5 Machine Vision IMAQ Vision for LabWindows/CVI User Manual 5-12 ni.com These functions require you to inpu t the coordinates of the points alo ng the search contour . Use imaqROIProfile() to obtain the coordinates along the edge of each contour in an R OI.
Chapter 5 Machine Vision © National Instruments Corporation 5-13 IMAQ Vision for LabWindows/CVI User Manual Finding Points Using Pattern Matching The pattern matching algorith ms in IMA Q V ision measure the similarity between an idealized representation of a feature, called a template, and the feature that may be present in an image.
Chapter 5 Machine Vision IMAQ Vision for LabWindows/CVI User Manual 5-14 ni.com Figure 5-7. Symmetry Feature detail A template with relatively coarse features is less sensitive to variations in size and rotation than a model with fine features. However, the model must contain enough detail to identify it .
Chapter 5 Machine Vision © National Instruments Corporation 5-15 IMAQ Vision for LabWindows/CVI User Manual Background information Unique background information in a template improves search performance and accuracy.
Chapter 5 Machine Vision IMAQ Vision for LabWindows/CVI User Manual 5-16 ni.com incorrect results. To avoid this, reduce the search area so that only the desired pattern lies within the search area. The time required to locate a pattern in an im age depends on both the template size and the search area.
Chapter 5 Machine Vision © National Instruments Corporation 5-17 IMAQ Vision for LabWindows/CVI User Manual However, there may be applications in whi ch the assumptions used in the algorithm are not optimal. Knowing your particular application and the images you want to process is useful in selecting the pattern matching parameters.
Chapter 5 Machine Vision IMAQ Vision for LabWindows/CVI User Manual 5-18 ni.com T esting the Search Algorithm on T est Images To determine if your selected templat e or reference pattern is appropriate for your machine vision ap plication, test the temp late on a few test images by using imaqMatchPattern() .
Chapter 5 Machine Vision © National Instruments Corporation 5-19 IMAQ Vision for LabWindows/CVI User Manual Color pattern matching retu rns the location of the center of the template and the template orientation. Follow these general steps to f ind features in an image using co lor pattern match ing: 1.
Chapter 5 Machine Vision IMAQ Vision for LabWindows/CVI User Manual 5-20 ni.com Feature Detail A template with relatively coarse features is less sensitive to variations in size and rotation than a model with fine features. However, the model must contain enough detail to identify it .
Chapter 5 Machine Vision © National Instruments Corporation 5-21 IMAQ Vision for LabWindows/CVI User Manual The training or learning process is time-intensi ve because the algorithm attempts to find optimal features of the template f or the particular matching process.
Chapter 5 Machine Vision IMAQ Vision for LabWindows/CVI User Manual 5-22 ni.com Figure 5-12. Selecting a Search Area for Color Pattern Matc hing The time required to locate a pattern in an im age depends on both the template size and the search area.
Chapter 5 Machine Vision © National Instruments Corporation 5-23 IMAQ Vision for LabWindows/CVI User Manual The following are some elements in the IMA Q V ision p attern matching algorithm and how th.
Chapter 5 Machine Vision IMAQ Vision for LabWindows/CVI User Manual 5-24 ni.com Note Use the IMAQ_CONSERVATIVE strategy if you hav e multiple targets located v er y close to each other in the image. Decide on the best strategy b y experimentin g with the different options.
Chapter 5 Machine Vision © National Instruments Corporation 5-25 IMAQ Vision for LabWindows/CVI User Manual reference pattern in all cases, you have selected a good template. Otherwise, refine the current template, or select a better template until both training and testing are successful.
Chapter 5 Machine Vision IMAQ Vision for LabWindows/CVI User Manual 5-26 ni.com Convert Pixel Coordinates to Real-W orld Coordinates The measurement points you located with edge detection and pattern matching are in pixel coordinates.
Chapter 5 Machine Vision © National Instruments Corporation 5-27 IMAQ Vision for LabWindows/CVI User Manual Analytic Geometr y Measurements Use the following functions to make geometri cal measurements from the points you detect in the image: • imaqFitLine() — Fits a line to a set of points and computes the equation of the line.
Chapter 5 Machine Vision IMAQ Vision for LabWindows/CVI User Manual 5-28 ni.com Use imaqFindLCDSegments() to calculate the regions of interest around each digit in an LCD or LED. T o find the area of each digit, all the segments of the indicator must be activ ated.
Chapter 5 Machine Vision © National Instruments Corporation 5-29 IMAQ Vision for LabWindows/CVI User Manual Y ou can configure the following processing functions to ov erlay different types of inform.
© National Instruments Corporation 6-1 IMAQ Vision for LabWindows/CVI User Manual 6 Calibration This chapter describes how to calibrate yo ur imaging system, save calibration information , and attach calibration informati on to an image. After you set up your imaging system, you may want to calibrat e your system.
Chapter 6 Calibration IMAQ Vision for LabWindows/CVI User Manual 6-2 ni.com Defining a Calibration T emplate You can define a calibration templat e by supplying an image of a grid or providing a list of pixel coordinat es and their corresponding real-world coordinates.
Chapter 6 Calibration © National Instruments Corporation 6-3 IMAQ Vision for LabWindows/CVI User Manual The origin, expressed in pixels, def ines the center of y our coordinate system. The angle specifies the orientation of your coordinate system with respect to the angle of the topmost row of dots in the grid image.
Chapter 6 Calibration IMAQ Vision for LabWindows/CVI User Manual 6-4 ni.com Figure 6-3. A Calibration Grid and an Image of the Grid Note If you specify a list of points instead of a grid for the calibration process, the software def ines a default coordinate system, as follows: 1.
Chapter 6 Calibration © National Instruments Corporation 6-5 IMAQ Vision for LabWindows/CVI User Manual Figure 6-4. Defining a Coordinate System Learning Calibration Information After you def ine a calibration grid and reference axis, acquire an image of the grid using the current imaging setup .
Chapter 6 Calibration IMAQ Vision for LabWindows/CVI User Manual 6-6 ni.com Specifying Scaling Factors Scaling factors are the real-world distances between the dots in the calibration grid in the x and y d irections and the units i n which the distances are measured.
Chapter 6 Calibration © National Instruments Corporation 6-7 IMAQ Vision for LabWindows/CVI User Manual IMAQ_PERSPECTIVE to choose the perspecti ve calibration algorithm. Learning and applying perspect i ve projection is less com putationally intensi ve than the nonlinear method.
Chapter 6 Calibration IMAQ Vision for LabWindows/CVI User Manual 6-8 ni.com Also, adjust the range pa rameter to distinguish t he dots from the background. 3. Select another learning algorithm. When no nlinear lens distortion is present, using perspecti ve projection sometimes results in a lo w learning score.
Chapter 6 Calibration © National Instruments Corporation 6-9 IMAQ Vision for LabWindows/CVI User Manual Simple Calibration When the axis of your camera is perpendicular to the image plane and lens distortion is negligibl e, use simple calibration.
Chapter 6 Calibration IMAQ Vision for LabWindows/CVI User Manual 6-10 ni.com Save Calibration Information After you learn the calibration inf ormation, you can save it so that you do not have to relearn the information f or subsequent processing.
© National Instruments Cor poration A-1 IMAQ Vi sion for LabWindows/CVI User Manual A T echnical Support Resources W eb Support National Instruments W eb support is your first stop for help in solving installation, configuration, and application pro blems and questions.
Appendix A T echnical Support R esources IMAQ Vision for LabWindows/CVI User Manual A-2 ni.com W orldwide Support National Instruments has of fices located around the world to help address your support needs. Y ou can access our branch off ice W eb sites from the W o rldwide Of fices section of ni.
© National Instruments Cor poration G-1 IMAQ Vision for LabWindows/CVI User Manu al Glossar y Numbers/Symbols 1D One-dimensional. 2D T wo-dimensi onal. 3D Three-dimensional. A AIPD National Instruments pro prietary image file format used for saving complex images and calibration inform ation pertaining to step and spatial units (extension APD).
Glossary IMAQ Vision for LabWindows/CVI User Manual G-2 ni.com B b Bit. One binary d igit, either 0 or 1. B Byte. Eight related bits of data, an eight-b it binary number .
Glossary © National Instruments Cor poration G-3 IMAQ Vision for LabWindows/CVI User Manu al brightness (1) A constant added to the red, green, and b lue 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 objects.
Glossary IMAQ Vision for LabWindows/CVI User Manual G-4 ni.com CLUT Color lookup table. T able for conv erting the value of a pixel in an image into a red, green, and blue (RGB) i ntensity . color images Images containing color inform ation, usually encoded in the RGB form.
Glossary © National Instruments Cor poration G-5 IMAQ Vision for LabWindows/CVI User Manu al cross correlation A technique that compares the similar ity of two images or parts of an image. Y ou can use cross correlation to find the optimal position where similarity exists.
Glossary IMAQ Vision for LabWindows/CVI User Manual G-6 ni.com E edge Defined b y a sharp chang e (transition) in the pixel intensities in an image or along an array of pix els. edge contrast The dif ference betw een the a verage pixel intensity before and the a verage pixel intensity after the edge.
Glossary © National Instruments Cor poration G-7 IMAQ Vision for LabWindows/CVI User Manu al form W indo w or area on the screen on which you place controls and indicators to create the user interface for your p rogram. Fourier spectrum The magnitu de information of the Fourier transform of an image.
Glossary IMAQ Vision for LabWindows/CVI User Manual G-8 ni.com H highpass attenuation Applies a linear attenuation to the frequencies in an image, wit h no attenuation at the highest frequency and full attenuation a t the lo west frequency . highpass FFT filter Remov es or attenuates low frequencies present in the FFT domain of an image.
Glossary © National Instruments Cor poration G-9 IMAQ Vision for LabWindows/CVI User Manu al hue offset angle The value added to all hue values so that the discontinuity occurs outside the values of interest during analysis .
Glossary IMAQ Vision for LabWindows/CVI User Manual G-10 ni.com image visualization The present ation (display) of an image (image data) to the user . imaging Any proces s of acquiring and displaying images and analyzing image data. IMA Q Image Acquisition.
Glossary © National Instruments Cor poration G-11 IMAQ Vision fo r LabWindows/CVI User Manual J JPEG Joint Photographic Expert s Group. Image file format for storing 8-bit and color images with lossy comp ression (extension JPG). K kernel Structure that represents a pixel and its relationship to its neighb ors.
Glossary IMAQ Vision for LabWindows/CVI User Manual G-12 ni.com logic operators The image operations AND, NAND, OR, XOR, NOR, XNOR, difference, m a s k ,m e a n ,m a x ,a n d m i n . lossless compression Compression in which the decompressed image is identical to the original image.
Glossary © National Instruments Cor poration G-13 IMAQ Vision fo r LabWindows/CVI User Manual match score A number ranging from 0 to 1000 that ind icates ho w c losely an acquired image matches the template image. A match score of 1000 indicates a perfect match.
Glossary IMAQ Vision for LabWindows/CVI User Manual G-14 ni.com Nth order filter Filters an image using a nonlinear f ilter . This filter orders (or classif ies) the pixel v alues surroun ding the pixel being processed. The pixel being processed is set to the Nth pixel v alue, wh ere N is the order of the filter .
Glossary © National Instruments Cor poration G-15 IMAQ Vision fo r LabWindows/CVI User Manual particle A connected region or grouping of pixels in an image in which all pixels hav e the sam e intensity lev el. Particles are also re ferred to as blobs or objects.
Glossary IMAQ Vision for LabWindows/CVI User Manual G-16 ni.com pyramidal matching A technique used to increase the speed of a pattern matchi ng algorithm by matching subsampled versions of the image and the reference pattern. Q quantitativ e analysis Obtaining various measurements of objects in an image.
Glossary © National Instruments Cor poration G-17 IMAQ Vision fo r LabWindows/CVI User Manual rotation-inv ariant matching A pattern matching technique i n which the reference pattern can be located at any orientation in t he test image as well as rotated at any de gree.
Glossary IMAQ Vision for LabWindows/CVI User Manual G-18 ni.com spatial resolution The num ber of pixels in an image, in terms of the number of rows and columns in the image. square function See exponential function . square root function See lo garithmic function .
Glossary © National Instruments Cor poration G-19 IMAQ Vision fo r LabWindows/CVI User Manual V v al ue The grayscale intensity of a color pixel computed as the av erage of t he maximum and minimu m red, green, and blue values of that pixel. W watershed A technique used to segment an image into multiple regions.
© National Instruments Cor poration I-1 IMAQ Vision for LabWindows/CVI User Manual Index A acquiring measurement-ready images. See measurement-ready images, acquiring.
Index IMAQ Vision for LabWindows/CVI User Manual I-2 ni.com defining template images, 5-19 t o 5-20 setting matching parameters and tolerances, 5-22 to 5-24 color score weight, 5-24 color sensitivity,.
Index © National Instruments Cor poration I-3 IMAQ Vision for LabWindows/CVI User Manual lowpass, 2-10 lowpass frequency, 2-12 Nth order, 2-11 finding measurement points.
Index IMAQ Vision for LabWindows/CVI User Manual I-4 ni.com imaqAdd() function, 2-4 to 2-5 imaqAddRectContour() fu nction, 3-6 imaqArrayToComplextPlane() funct ion, 2-13 imaqArrayToImage() function, 2.
Index © National Instruments Cor poration I-5 IMAQ Vision for LabWindows/CVI User Manual imaqLightMeterPoint() functi on, 3-6, 3-7 imaqLightMeterRect() function, 3-6, 3-7 imaqLineProfile() function, .
Index IMAQ Vision for LabWindows/CVI User Manual I-6 ni.com imaqWriteVisionFile() funct ion, 5-15, 5-25, 6-10 imgInterfaceOpen() function, 2-6 imgSessionOpen() function, 2-6 imgSnap() function, 2-6 in.
Index © National Instruments Cor poration I-7 IMAQ Vision for LabWindows/CVI User Manual pattern matching, 5-13 to 5-1 8 measurement-ready images, acquiring, 2-1 to 2-13 acquiring or reading images, .
Index IMAQ Vision for LabWindows/CVI User Manual I-8 ni.com S scaling factors, for calibrati on, 6-6 scaling method, for calibr ation, 6-8 search contour, finding points along e dge, 5-11 to 5-12 Selection tool (table), 3-2 source and destination images, 2-4 to 2-5 statistics.
An important point after buying a device National Instruments IMAQ Vision for Measurement Studio (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought National Instruments IMAQ Vision for Measurement Studio yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data National Instruments IMAQ Vision for Measurement Studio - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, National Instruments IMAQ Vision for Measurement Studio you will learn all the available features of the product, as well as information on its operation. The information that you get National Instruments IMAQ Vision for Measurement Studio will certainly help you make a decision on the purchase.
If you already are a holder of National Instruments IMAQ Vision for Measurement Studio, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime National Instruments IMAQ Vision for Measurement Studio.
However, one of the most important roles played by the user manual is to help in solving problems with National Instruments IMAQ Vision for Measurement Studio. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device National Instruments IMAQ Vision for Measurement Studio along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
