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ActivDataCode User`s Manual

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1. r Symbol Rows Min Max E AE ffs o p General Columns Min Max 3 Type Data Matrix ECC 200 y ASS o fra gt 18 Maximum Number of Symbols m Ea S Slant Max T IV Candidates 7 F fo gt Oo p Parameters Results Shape Current Default Detect and Teach M Auto Teach IZ Code P1 Rectande any 2 Reset W Position F e Current Default Load Save r Process Control Status Not found 7 Symbol Contrast P 4 Il teed a Rosito Pattern f Slant m f Unused Error Correction FF Print Growth rt Gap Current Default No or Small r No or Small 3 open parameter dialog 4 change parameter Figure 2 4 Tuning image processing parameters with the new settings We continue with the example on the next double page ActivVisionTools 3 2 Your Fast Track to Solutions 16 Using ActivDataCode Tuning Image Processing continued The following steps are visualized in figure 2 5 on page 17 5 Contrast This parameter sets the minimum gray value difference between foreground and background modules Decrease this value if the data code is not detected because of low contrast If the data codes in your application are of high contrast you can increase the value to speed up the application To determine a suitable value interactively pick the gray values of sample foreground and background positions using the Zoom tool To open it click on the image w
2. Lo o oO 8 off lt 8 Contrast off high O x Preprocessing Smoothing Ho Growth gt Joo Contrast 4 gt Jo al I Compensate for Low Resolution IV Apply Preprocessing IV Display Figure 2 9 Applying the preprocessing filters ActivVisionTools 3 2 Your Fast Track to Solutions 26 Using ActivDataCode ActivDataCode 2008 04 23 Chapter 3 Combining ActivDataCode with other ActivVisionTools While the previous chapter explained how to read data codes this chapter focuses on how to further evaluate and output the results using other ActivVisionTools How to access results and evaluations via the programming interface is described in chapter 4 on page 35 In the corresponding Visual Basic projects the task is to read and evaluate a seguence of data codes 3 1 Converting Results to Other Units 28 3 2 Evaluating Results lt lt o o 30 343 Output of Results ks k ks a k ses 32 27 ActivDataCode 28 Combining ActivDataCode with other ActivVisionTools Visual Basic Example 3 1 Converting Results to Other Units Using gt Up to now the position of a data code was measured in image coordinates i e pixels Using AVTViewCalibration you can convert this information into other units Note that for a more accurate calibration you should employ ActivGeoCa
3. To draw the ROI move the mouse in the image while keeping the left mouse button pressed Please experiment at this point with the different shapes The creation of a polygonal ROI lt is more complex By the first mouse movement the first side of the polygon is created You can add a new corner point by clicking on the line with the left mouse button when you drag it by keeping the mouse button pressed new polygon sides are created where you can again add new corner points To delete a corner point drag it onto a neighboring corner point If the data code moves from image to image we recommend to enlarge the ROI accord ingly You can now move the ROI by dragging its pick point in the middle By dragging the outer pick points you modify its shape Again please experiment to get familiar with the ROIs Note that for a polygonal ROI the middle point appears at the center of gravity of the ROI and therefore changes whenever the polygon is modified besides it ActivDataCode 2008 04 23 2 1 Specifying Regions of Interest 9 i Creating Regions of Interest Maximum Number of Symbols fr gt y 3 0 m Parameters 3 Detect and Teach f Auto Teach Reset Details Load Save Status Not found m gt Copy Paste Delete Delete All m Select ActivVisionT ool JAVTDataCodet Region of Inter
4. the read code should now be displayed in AVTView If AVTDataCode fails to extract a data code AVTDataCode will display a corresponding message With the help of check boxes you can specify what is to be displayed on the image the decoded data of the data code the image region corresponding to the data code excluding the quiet zone You can also display both the foreground and the background zero modules Especially with difficult images it can be helpful to display all the candidates that are evaluated by ActivDataCode Section 4 1 on page 36 explains how to change the appearance of the displayed results Besides the extracted data code ActivDataCode can output additional information also called features e g the position of the data code The process control features are explained in appendix A on page 51 ActivDataCode 2008 04 23 2 2 Reading Data Codes 11 3 visualize certain results in the image O select the data code type 2 extracted codes are displayed otherwise 4 choose results for the spreadsheet an eror message appears i Reading Data Codes 5 x Maximum Number of Symbols m Parameters Teach 7 Auto Teach Reset Details Load Save IV Code I Region IV Modules TF Zero Modules TF Candidates IV Preprocessing L Lo e oO y S a E lt Select
5. 34 Combining ActivDataCode with other ActivVisionTools 12 06 05 16 21 21 AVTDataCode1 yes Rectangle1 1 yes O yes Data cla502976 Symbol Contrast yes 0 200507 0 200000 1 000000 Number Unused Error Correction yes 1 000000 0 200000 1 000000 Number 12 06 05 16 21 22 AVTDataCode1 no Rectangle1_1 no 0 no Symbol Contrast no 0 171800 0 200000 1 000000 Number Unused Error Correction no 0 166667 0 200000 1 000000 Number 12 06 05 16 21 22 AVTDataCode1 no Rectangle1_1 no O no Symbol Contrast no 0 195253 0 200000 1 000000 Number Unused Error Correction yes 1 000000 0 200000 1 000000 Number 12 06 05 16 21 22 AVTDataCode1 yes Rectangle1 1 yes O yes Data tre502971 Symbol Contrast yes 0 228574 0 200000 1 000000 Number Unused Error Correction yes 0 333333 0 200000 1 000000 Number 12 06 05 16 21 23 AVTDataCode1 yes Rectangle1 1 yes O yes Data tre502973 Symbol Contrast yes 0 213203 0 200000 1 000000 Number Unused Error Correction yes 0 833333 0 200000 1 000000 Number 12 06 05 16 21 23 AVTDataCode1 yes Rectangle1 1 yes O yes Data tre502974 Symbol Contrast yes 0 238092 0 200000 1 000000 Number Unused Error Correction yes 0 500000 0 200000 1 000000 Number Figure 3 4 Part of an example log file ActivDataCode 2008 04 23 Chapter 4 Tips Tricks This chapter contains additional information that facilitates working with ActivDataCode e g how to modify the graphical display of results and ho
6. AVTDataCode1 y Finish Private Sub AVTDataCodel Finish atToolResults As ACTIVVTOOLSLib IAVTToolResult ActivDataCode Figure 4 3 Creating a procedure to handle the event Finish The variable atToolResults contains the result data for all ROIs of your instance of AVTData Code The current number of ROIs can be queried via Dim iNumROIs As Integer iNumROIs atToolResults ROINum In Visual Basic NET the event handler has a different signature Private Sub AxAVTDataCode1 Finish ByVal sender As Object _ ByVal e As _ AxActivVTools __AVTDataCode_FinishEvent _ Handles AxAVTDataCode1 Finish A first difference is that tool names start with the prefix Ax i e AVTDataCode becomes AxAVT DataCode The main difference however is that the tool results are not directly passed instead they are encapsulated in the parameter e From there they can be extracted with the following lines Dim atToolResults As AVTToolResult atToolResults e atToolResults To use classes like ACTIVVTOOLSLib AVTToolResult without the namespace ACTIVVTOOL ActivVisionTools 3 2 Your Fast Track to Solutions 42 Tips 8 Tricks SLib as in the code above you must import this namespace by inserting the following line at the very beginning of the code more information about importing namespaces can be found in the Advanced User s Guide for ActivVisionTools in section 1 2 4 5 on page 12 Imports ACTIVVTOOLSLib The results of a certai
7. Smali eee fi Figure 1 5 The advanced sub tools of ActivDataCode B AVTDataCodeSettings is a support tool of ActivDataCode With it you can set up what is to be displayed in Activ View and what results are to be calculated for ActivDecision How to use AVTDataCodeSettings is described in section 2 2 on page 10 Ei AVTDataCodePreprocessing is a support tool of ActivDataCode It allows to apply image preprocessing to the ROI in order to enable or improve the decoding of data codes under bad conditions How to use AVTDataCodePreprocessing is described in section 2 5 on page 22 AVTDataCodeParameters is a support tool of ActivDataCode It allows to manually tweak the parameters of ActivDataCode for advanced applications How to use AVTDataCode Parameters is described in section 2 4 on page 14 e sr ActivDataCode 2008 04 23 Chapter 2 Using ActivDataCode ActivDataCode This chapter will explain how to use ActivDataCode to read various types of data codes and how to tune the underlying image processing The corresponding Visual Basic projects show how to successfully read data codes 2 1 Specifying Regions of Interest o oo o 8 2 2 Reading Data Codes as 10 2 3 Teaching Data Codes ooo o 12 2 4 Tuning Image Processing o eee eee ccc 14 2 5 Preprocessing Images ooo o 22 Using ActivDataCode Visu
8. allows to monitor the wear and tear of the marking station itself and detect defects and other problems This way reliable labeling of parts with high quality can be achieved Images acquired for data code verification should be of high quality and higher resolution than actually needed for reading purposes A module size of at least 5 pixels is recommended ActivDataCode 2008 04 23 A 3 International Standards 53 A 3 International Standards There are several international standards that deal with data code verification The fundamentals incorporated in implementing the process control features of ActivDataCode are mostly derived from the following international standards e ISO IEC 15415 Information technology Automatic identification and data capture technigues Bar code print guality test specification Two dimensional symbols e ISO IEC 16022 Information technology International symbology specification Data matrix e ISO IEC 18004 Information technology Automatic identification and data capture techniques Bar code symbology QR Code e AS 9132 Quality management systems Data Matrix quality Requirements for Parts Marking It is very important to note that ActivDataCode does not fully implement these standards Thus ActivDataCode cannot be used to verify that data codes are compliant with any of these standards The listed standards require the calculation of the process control fe
9. can indicate if gaps are allowed and to what degree Set to Any if both very tight and very loose data codes should be detected Optimizing the Parameters of a Detected Data Code As soon as a data code is decoded its actual parameter values are displayed in the parameter dialog You can then optimize the parameters manually If no teaching has been performed yet you can also click the Teach button to snap the parameters to the current values Optimizing the parameters will speed up your application value of current data code Rows 16 Min Max Ae aaa e optimizing Rows 16 Min Max r Tae e ActivDataCode 2008 04 23 2 4 Tuning Image Processing 21 r Module Size Min Mas m ai e IR B Aspect Min Max Y ama afo E No or Sr y Size 45 Aspect EA RSP Gap r Figure 2 7 Tuning image processing parameters cont ActivVisionTools 3 2 Your Fast Track to Solutions ActivDataCode 22 Using ActivDataCode Visual Basic Example 2 5 Preprocessing Images Using Ei In some cases the guality of the acguired images is so bad that a data code cannot be read In other cases the data code itself might be damaged e g stamped written upon or distorted If both teaching and manual parameter tweaking fail to produce any results you may try to preprocess the image itself using various filters Keep in mind to follow this approach only as a last resort In general images
10. code extraction and of their eval uation via the programming interface With this you can e g realize an application specific graphical user interface perform additional processing on the results or send results to a spe cial output device Detailed information about the programming interface can be found in the Reference Manual As in the previous sections the examples stem from Visual Basic 6 0 if the ActivVisionTools specific code differs in Visual Basic NET the corresponding lines are also shown for the first appearance only For other NET languages or C please refer to the Advanced User s Guide for ActivVisionTools section 1 2 3 on page 5 and section 1 3 4 on page 28 respectively Please note that we assume that readers of this part have at least a basic knowledge of Visual Basic To work with the programming interface in Visual Basic 6 0 you must first add the Activ VisionTools type library to the project s references by checking the box labeled Activ VisionTools Type Library in the Visual Basic menu dialog Project gt References In Visual Basic NET the reference is added automatically References datacode_resultaccess vbp x Available References M Visual Basic For Applications M Visual Basic runtime objects and procedures Ml Visual Basic objects and procedures M OLE Automation MiactivvisionTools 3 1 Type Library CO IAS Helper COM Component 1 0 Type Library O IAS RADIUS Protocol 1 0 Type Lib
11. enabled This way you can immediately see any detec tion improvements caused by preprocessing changes 4 In AVTDataCodePreprocessing check v Apply Preprocessing to enable image preprocessing This activates the preprocessing filters The preprocessing is only applied to the ROIs 5 Check v Display to visualize the preprocessing changes in the image ActivDataCode 2008 04 23 2 5 Preprocessing Images 23 O let ActivDataCode try to detect the displayed data code 2 visualize all data code properties i Preprocessing Images p olx rm Display IV Code IV Region IV Modules IV Zero Modules IV Candidates IV Preprocessing m Results IV Code IV Type Information IV Position T Appearance m Process Control T Symbol Contrast J Axial Nonuniformity JP Slant T Grid Nonuniformity f Unused Error Correction J Print Growth TF Grades No code detected in current image Possible reasons include Code is not present or not within ROI A General Code is not of selected type Data Matrix ECC 200 p Preprocessing Image quality is not good enough improve setup Smoothing A a fo al Type fi Symbol quality is not good enough try preprocessing Maximum Nu Growth 4 foo Contrast gt Jo al I Compensate for Low Resolution v 3 o oO o o a 5 O lt m Parameters IV Apply Preprocessing IV Dis
12. of bad guality are the result of a poor image acguisition setup Improper lighting causing reflections or uneven contrast cameras oriented at an angle leading to vari ous distortions or even unsuitable camera lenses or positioning capturing images too small or too noisy all influence the reliability of ActivDataCode Some of the defects caused by these weaknesses cannot be restored retrospectively Thus it is usually much more effective to rectify the way images are acguired Preprocessing is not a panacea and it slows down image processing considerably Preparation for the following example If you worked on the previous example you may continue using this project Add AVTDataCodePreprocessing to the form by double clicking EJ Otherwise open the project preprocessing datacode_preprocessing vbp Execute the application Run gt Start or via the corresponding button and load the image datacode ecc200 ecc200_preprocess seq Open AVTViewROI by se lecting Region of Interest in the popup menu and place an ROI over the data code The following steps are visualized in figure 2 8 O Click Detect and Teach in AVTDataCode ActivDataCode tries to detect the data code but fails A corresponding message is displayed 2 Check v Auto Teach to automatically adapt the parameters of ActivDataCode to the changes from the preprocessing filters G Make sure all visualizations are
13. r Results ActivVisionT ool JAVTDataCodet ROI EE IV Code IV Type Information IV Position TF Appearance m Process Control T Symbol Contrast J Axial Nonuniformity T Slant 7 Grid Nonuniformity gt TF Unused Error Correction FE Print Growth TF Grades Length Type Objectld Data jo HD 7100 160GB 13 QR Code Model 2 Version 1 Level V Enable Update Unit Pixel gt 5 select AVTDataCode1 in the combo box 7 6 select the ROI whose results and enable the update of results is then displayed Figure 2 2 Reading data codes and selecting results To view the calculated features select the tool whose results to display in the combo box ActivVisionTool and enable the update of results in AVTDataView If there is only one tool it is selected automatically 6 Automatically a list of the ROIs of AVTDataCode1 appears below Select the ROIs whose results you want to examine by checking their box Their results are then dis played in a table the columns corresponding to the selected features ActivVisionTools 3 2 Your Fast Track to Solutions 12 Using ActivDataCode Visual Basic Example 2 3 Teaching Data Codes Using Er The default values of the parameters of ActivDataCode are selected so that a broad range of data codes can be decoded without any user intervention If a specific data code fails to fit within the boundaries of these default settings
14. the line by dragging its pick points For fine positioning zoom the image and move the displayed part using the scrollbars to the right and below the image Select a unit in the combo box Unit ofAVTViewCalibration O ActivDataCode 2008 04 23 3 1 Converting Results to Other Units 29 ra select AVTViewCalibration1 3 to draw the line in the image move the mouse while pressing the left button 2 click to create a line shaped ROI 4 edit the line by dragging the pick points Ox i Converting Units r Edit Region of Interest yy lt e 2 Fale p Paste o elete Delete All Select ActiWisionTao AvIvientalbraton Region of Interest Line 1 121 E 2417 Locked Unit Length Line Boo cm K PixelHeight 0 012159 cm Name User Defined Mode 20 Calibration Save Load Reset Select aa i Spb Wi Sa ee Eo cm ActivDataCode ActivDataCode 13 a Matrix ECC 200 16 3 216 3 757 112 057 2 152 IV Enable Update Unit select a unit in the combo box specify the length of the line O results are converted into the selected unit the computed pixel size is displayed Figure 3 1 Converting positions into other units 6 Specify the length of your line in the example 3 1cm in the text box Length Line and press Enter AVTViewCalibratio
15. you can ask ActivDataCode to adjust the parameters to fit Furthermore using a set of prototypical images you can optimize the parameters to suit your application in the most efficient way The more stable the appearance and quality of the data codes in your application the faster the processing Preparation for the following example If you worked on the previous example you may continue using this project Add AVTViewFG to the form by double clicking You may delete AVTDataView if required you can re open it at run time by clicking into AVTDataCode with the right mouse button and selecting Data View Otherwise open the project teaching datacode_teaching vbp Execute the application Run gt Start or via the corresponding button Select the image sequence datacode ecc200 ecc200_teach seq in the combo box In put File Remember to set the data code type back to Data Matrix ECC 200 for this example The following steps are visualized in figure 2 3 Use the Single button to step through the sequence of images Stop at the first image where the data code is not decoded If a data code cannot be decoded click Detect and Teach ActivDataCode will try to adjust its internal parameters to read the displayed data code Please note that the parameters will snap to the properties of that very data code the first time the button is clicked As a result data codes wh
16. Modules oO Device I Candidates IV Preprocessing S Ema E AAA A r Results gt r Input File V Code IV Type Information 3 dstacode ece200 sec200_teachseq 1 Pion T Appearance lt q z Choose Directory Choose File Process Control 3 f Symbol Contrast J Axial Nonuniformity p Grabbing I Slant I Grid Nonuniformity Execute L Stop V Connected More Parameters 7 Unused Error Correction 4 T Single Run Trigger Save Image Save Window J Print Growth Grades 98 6 ms Loading file ecc200_teach_02 4 train remaining images 3 let ActivDataCode detect subseguent data codes automatically 5 save the trained parameters Figure 2 3 Teaching data codes 4 Click the Run button to teach the remaining images of the sequence If all images are trained click the Stop button You can track the file names of the seguence file by looking at the status bar The data code model is saved automatically when the application quits You can also explicitly save the model of the trained data codes at any time To do this click the Save button and enter a file name The default extension of these files is dmd data code model description ActivVisionTools 3 2 Your Fast Track to Solutions 14 Using ActivDataCode 2 4 Tuning Image Processing Using Normally there is no need to touch the internal paramete
17. TViewExecute Besides accessing the results of data code extraction the project code contains additional func tionality which is explained briefly in the following Note that the code is only shown for Visual Basic 6 0 a Visual Basic NET application with result access can be found in the directory examples dotnet vb datacode_results First of all the extracted code and the unused error correction is only to evaluated if exactly one object has been extracted ActivVisionTools 3 2 Your Fast Track to Solutions L Lo e oO y S a E lt 44 Tips amp Tricks If iNumObjects 1 Then sCode atROlResult ObjectValue handleCode 0 LabelCode Caption sCode dUEC atROlResult ObjectValue handleUEC 0 Else LabelCode Caption lt multiple gt Call SetAlarm End If If not exactly one object is extracted the function SetAlarm stops the application by setting AVTView s property RunState to False and switches the color of the status element below the image to red The function ClearAlarm resets the color to green To test this behavior step through the images sequence to an image containing two data codes Private bIsError As Boolean Private Function SetAlarm AVTView1 RunState False Light BackColor vbRed bIsError True End Function Private Function ClearAlarm Light BackColor vbGreen bIsError False End Function When calculating the mean unused error correcti
18. User s Manual AcriDataCoDE Fast Easy Reliable Microsoft Windows Windows NT Windows 2000 Windows XP Visual Basic Microsoft NET Visual C Visual C and ActiveX are either trademarks or registered trademarks of Microsoft Corporation All other nationally and internationally recognized trademarks and tradenames are hereby rec ognized EC Copyright 2005 2008 by MVTec Software GmbH M nchen Germany mvrec software cmb Edition 1 February 2006 ActivVisionTools 3 1 Edition 2 May 2008 ActivVisionTools 3 2 All rights reserved No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without prior written permission of the publisher More information about ActivVisionTools can be found at http www activ vision tools com How to Read This Manual This manual explains how to use ActivDataCode to read 2D data codes It describes the func tionality of ActivDataCode and its cooperation with other ActivVisionTools with Visual Basic examples Before reading this manual we recommend to read the manual Getting Started with ActivVision Tools which introduces the basic concepts of Activ Vision Tools and the User s Man ual for ActivView to learn how to load and display images To follow the examples actively first install and configure ActivVisionTools as described in the manual Getting Star
19. aCode provides three support tools In figure 1 4 the basic tools are depicted together with other ActivVisionTools that you will use in a typical Activ DataCode application In figure 1 5 on page 6 the tools for advanced data code applications can be seen ActivView vn AVTDataCode r General Type Data Matrix ECC 200 he Maximum Number of Symbols fi m Parameters o Teach 7 Auto Teach o Reset Load Q Details Save S r Status OK 6 lt Edit Region of Interest r Display m m lt lt IV Code IV Region Y Modules T Zero Modules Copy Pate Delete Delete ll I Candidates IZ Preprocessing r Select r Results ActivVisionT ool AWTDataCodel y F Code RAON Region of Interest Rectangle1 1 Weel IV Position I Appearance 4 gt Locked Process Control 7 Symbol Contrast Axial Nonuniformity I Slant f Grid Nonuniformity J Unused Error Correction J Print Growth I Grades ActivDecision AVTDataCodeSettings Figure 1 4 The basic sub tools of ActivDataCode together with suitable other tools AVTDataCode is the master tool of ActivDataCode In it you specify the expected type of data En code and the number of symbols to be decoded If a data code cannot be detected using the standard settings you can ask ActivDataCode to adjust its internal parameters
20. al Basic Example 2 1 Specifying Regions of Interest Using t ActivDataCode lets you choose between different shapes of ROIs e g arbitrarily oriented rect angles or ellipses You create an ROI using AVTViewROI which is a support tool of ActivView Preparation for the following example Open the project rois datacode_rois vbp Alternatively create a new project and place the following tools on the form in parentheses the icon you have to double click with the left mouse button AVTView Ci AVTViewROI ad and AVT DataCode Ex Execute the application Run gt Start or via the corresponding button Open AVTViewFG by clicking into AVTView with the right mouse button and se lecting Image Acquisition in the popup menu Load the image data codeNgrcodeNgr hd 01 via the combo box Input File The following steps are visualized in figure 2 1 o e First you have to tell AVTViewROI to create an ROI for ActivDataCode by selecting the corresponding entry in the combo box ActivVisionTool In this box all ActivVision Tools are listed that have been placed upon the form By default the tools are referenced by the name of the corresponding ActiveX control plus a counter to distinguish between multiple instances of a control on the form e g AVTDataCode1 If there is only one tool it is selected automatically Next select the desired shape of the ROI for example a rectangle
21. ast data codes have been designed to be easily readable by the eyes of machines namely cameras and specialized scanners In this regard they are very similar to bar codes which also encode information in a way that makes it easy for machines to decipher What separates them is the amount of information that can be encoded without the symbol getting too big in size as well as the reliability with which even defective data codes can be decoded In general data codes are used in applications where a significant amount of information is to be associated with objects Plus the information needs to be in place i e printed on or punched into the object Otherwise it would be sufficient to label the object with a product code and look up the associated information in a data sheet or database which is typical for applications based on bar codes Concepts There are different types of data codes Whereas bar codes encode the information as an alter nating pattern of black and white along a line data codes add an additional dimension storing the information in a grid or matrix The elements or cells that form this matrix are referred to as modules These modules carry binary information They can be set or unset In this manual unset modules will be referred to as zero modules By default a dark module is considered to be set whereas a light module marks an unset bit This is referred to as the polarity of a data code In some cases the po
22. atToolResults As already remarked in the previous section tool names are prefixed with Ax thus you must search for the results of AxAVTDataCode1 If atToolResult name AxAVTDataCode1 Then You can query the overall evaluations at different levels tool ROI or object Dim atROlResult As AVTROIResult Dim bToolIsOK As Boolean bROIIsO0K As Boolean bObjIsOK As Boolean Set atROIResult atDataCodeResult ROIResults 0 bToolIsOK atDataCodeResult Evaluation bROIIsOK atROIResult Evaluation bObjIsOK atROIResult ObjEvaluation 0 Furthermore you can access the evaluation of individual features like the data code of the object with the ID 0 but also of tool features e g the evaluation of the number of bad ROIs or of ROI features e g the evaluation of the number of objects via the corresponding feature handle In contrast to object features the handles for tool and ROI features are available as properties of ACTIVVTOOLSLib AVTToolResult Dim handleCode As Integer handleBadROIs As Integer Dim handleObjectsInROI As Integer Dim bCodeIsOK As Boolean bBadROIsIsOK As Boolean Dim bObjectsInROIIsOK As Boolean handleCode AVTDataCode1 FeatureHandleCode handleBadROIs atDataCodeResult FeatureHandleBadROIs handleObjectsInROI atDataCodeResult FeatureHandleObjectsROI bCodeIsOK atROIResult ObjFeatureEvaluation handleCode 0 bBadROIsIsOK atDataCodeResult FeatureEvaluation handleBadROIs bObjectsInROIIsOK atROIRe
23. ate of results J 3 formulate conditions for objects 4 the evaluations are displayed immediately i Evaluation the Results of ActivDataCode 10 xj Results N ry Path AVTDataCode1 odel F Tool Features H Rectangle1_1 ROI Features Object O BETA AWTDataCodel AWTDataCodel B 6 check this box to show the used parameters 5 specify default conditions FTP Wy AWTDataCodel Objects Tool Number Good Objects Tool Number Bad Objects Tool Number Good ROIs Number Bad ROIs Number Rectanglel_1 Objects ROI Default Default Default IV Enable Update IV Fit Cell Size Good Objects ROI Default Default Default Bad Objects ROI Default Default Default Data Default Default Default Lenath Default Default String Type Symbol Width Object 0 IV Fit Cell Size Number Max Number None Objects ROI 1 1 Good Objects RO 0 100 Bad Objects ROI 0 0 Number Max Data HD 7100 080GB HD 7100 160GB String Max Length D 100 Number None Type AAA ZZZ String None None Unit Pixel Symbol Width 0 25 Number Figure 3 2 Formulating conditions to evaluate results If many similar objects are extracted that all should meet the same conditions you can specify default conditions using AVTDecisionViewDefaults Defaults can be set per tool or per ROI ROI defau
24. atures to be based on a reference decoding algorithm However ActivDataCode implements its own decod ing algorithm Its main use is in heavy duty data code reading that is robust even under bad conditions something that the reference decoding algorithm is neither capable of nor intended for That said the results from ActivDataCode nonetheless borrow from the listed standards and apply the same grading system Therefore they are very much comparable to results of data code verifiers actually implementing the standards A 4 Quality Grades The quality grades derived from evaluating the process control features are expressed on a scale from A to D plus a failing grade F with A representing the highest quality The overall quality grade of a data code is the lowest grade of all its individual process control features A 5 Available Features The calculation of the process control features is available from the AVTDataCodeSettings dialog The results can be inspected in the AVTDataView dialog see figure A 1 Both dialogs are available by right clicking on AVTDataCode in your application In the following sections ActivVisionTools 3 2 Your Fast Track to Solutions ActivDataCode 54 Process Control Features Process Control Ex ActivData iew AYTDataCode1 3 lol x IV Symbol Contrast JV Axial Nonuniformity Select Akos AVTDataCode1 y IV Slant IZ Grid Nonuniformity Y Unused Error Correctio
25. ction environments Another aspect of data code reading is to judge the guality of the data codes themselves It is the focus of this appendix Using data codes as a labeling technigue in industrial production flows and for retracement tracking purposes is all about automation A proper use will result in an increase in efficiency and lower production and maintenance costs Data codes of bad guality will work against these goals Therefore it is crucial that data codes used for these applications be of high guality The process of actually producing data codes and applying them to products or objects reguires immediate feedback to rank their guality in order to guarantee a certain standard of readability Getting this kind of feedback is known as data code verification ActivDataCode can be set up to calculate common features used for data code verification A 2 Data Code Production There are several methods to mark parts with data codes some of which include e ink jet printing e laser e dot peening e electro chemical etch ECE All these methods have their own advantages and deficiencies that influence their usefulness for different applications Selecting the right method for your application is beyond the scope of this manual Usually data code verification should be performed right at the marking station Not only does it offer a way to control the overall quality of the data codes with the ability to reject bad parts it also
26. e content of the selected file By checking v Enable Writing you enable the writing mode You can open the ActivFile s two dialogs DialogFileOptions and DialogOutput DataSelect by clicking File Options and Data Selection respectively In DialogFileOptions you can choose between two file formats Standard text files suffix txt and the so called comma separated values suffix csv which can be used as an input to Microsoft Excel Furthermore you can select a delimiter In the same dialog you can limit the size of the log file in form of the number of cycles that are to be recorded A cycle corresponds to one processing cycle from image input to the evaluation and output of results If you use this option ActivFile creates two log files and switches between them thus assuring that you can always access at least the results of the last N cycles N being the specified number of cycles By pressing Estimate you can let ActivFile estimate the size of one cycle Note that you must first select the output data in order to get meaningful results In the left part of DialogOutputDataSelect you can navigate through the result hi erarchy similarly to ActivDecision ActivDataCode 2008 04 23 3 3 Output of Results 33 O select the name of the log file 4 select file format and delimiter re check to enable writing 5 limit the file to a number of cycl
27. e way In the example project if an error is caused by the result access a dialog with the error description pops up and the function SetAlarm is called To view the effect of the error handler uncheck v Unused Error Correction in AVTDataCodeSettings so that the unused error correction is not calculated ActivDataCode Private Sub AVTDataCode1 Finish atToolResults As ACTIVVTOOLSLib IAVTToolResult variable declarations On Error GoTo ErrorHandler procedure body Exit Sub ErrorHandler Dim sTitle As String If Left Err Source 11 ActivVTools Then sTitle ActivVisionTools Error Else sTitle Runtime Error 4 CStr Err Number End If Call MsgBox Err Description vbExclamation sTitle Call SetAlarm End Sub By placing the following code at the beginning of the event handler the actual result access is restricted to the application mode With this mechanism you can setup the vision part of your application in the configuration mode without having to worry about run time errors ActivVisionTools 3 2 Your Fast Track to Solutions 46 Tips amp Tricks e If Not AVTView1 ExecutionMode eApplicationMode Then Exit Sub End If 4 3 2 Accessing Evaluation Results The evaluation results can be accessed similarly to the results of data code extraction in fact they are even stored in the same object However to access the evaluation results you now have to wait for ActivDecision
28. erface Process Control Features Al ire L 224 4 42 eat k a a ee k Contents A2 Dala Code Production lt ias aos e444 ion e aa 52 A3 Imematonal Standards i o c oa osa k A ak A A m 53 AA QUADS Grades co ss AR A A a 53 AS Ayalable FEBEM S 4 k aa a EA oe ds 53 Chapter 1 About ActivDataCode This chapter will introduce you to the features and the basic concepts of ActivDataCode It gives an overview about ActivDataCode s master tool and its support tools which are described in more detail in chapter 2 on page 7 and chapter 3 on page 27 11 Introducing ActivDataCode ooooo o oooooo o 1 2 The Sub Tools of ActivDataCode ActivDataCode 2 About ActivDataCode 1 1 Introducing ActivDataCode ActivDataCode enables you to develop applications to read various common data codes The tool finds data codes in your images and decodes them It returns the decoded data along with additional information about the data codes Following the tradition of its sibling tools it is easy to set up and employ Furthermore it is powerful enough to be used for advanced applications Basics A data code is a symbol with a certain meaning just like a letter or an icon There are data codes that represent the number 42 and there are data codes that represent the Japanese translation of The Fool on the Hill by The Beatles Most letters or icons have been designed to be perceived by humans In contr
29. es 3 click to open the dialogs 6 estimate the file size for ony cycle ii Writing Results to a Log File File Options Limitations Z I Limit File Size Maximum Bycles 10 File Options Data Selection Last estimated Data Size per Cycle joo KBytes Estimate IV Enable Writing 1 1 output Date Selection E General Tool ROI Object IV Date and Time IV Name IV Name Y Name I Tags IV okay IV okay IV okay Path AVTDataCode1 4 Rectangle1_1 Good Object Bad Objects L Lo e oO y S a E lt Good Objects Symbol Contrast Unused Error Correction Bad Objects aaa adan aariaa 0940000040 aaa aaa a411 Aana M 7 navigate through the results select the output data Figure 3 3 Customizing log files In the right part of DialogOutputDataSelect choose the output data by checking the corresponding boxes You may output different items depending on the evaluation of an object By clicking on the column labels with the right mouse button you can check or uncheck all boxes in the column similarly you can check or uncheck whole rows or all rows of a certain tool If you now step through the image sequence by clicking Single in AVTViewFG the log file is created Figure 3 4 shows part of an example log file ActivVisionTools 3 2 Your Fast Track to Solutions
30. est Rectangle1_1 141 m 2 7 Locked draw the ROI in the image by pressing the left mouse button and moving the mouse O select AVTDataCode1 in the combo box L Lo e oO y S a E lt edit the ROI by dragging the pick points 2 select a shape for the ROI you can copy paste and delete the selected ROI or delete all ROIs 600 step through the ROls of the selected tool with these buttons 7 lock the selected ROI Figure 2 1 Creating a region of interest may even lie outside the ROI for concave polygons To create a second ROI repeat step 2 You can also copy paste and delete the selected ROI or delete all ROIs 6 ROIs can be selected by clicking next to them in the image Alternatively use the two arrow buttons 4 fF to step through all the ROIs of the selected tool 7 By checking v Locked you can lock the selected ROI in place and thus prevent it from accidental editing or deletion If there are multiple data codes of the same type in an image you can either create one ROI that contains them all or multiple ROIs containing one or more data codes ActivVisionTools 3 2 Your Fast Track to Solutions 10 Using ActivDataCode Visual Basic Example 2 2 Reading Data Codes Using Ha While you are positioning an ROI on the image ActivDataCode already t
31. g image processing parameters cont We continue with the example on the next double page ActivVisionTools 3 2 Your Fast Track to Solutions 18 Using ActivDataCode Tuning Image Processing continued The following steps are visualized in figure 2 6 on page 19 Rows This parameter specifies the number of modules in vertical direction Depending on the parameter Shape it may be bound to Columns 9 Columns This parameter specifies the number of modules in horizontal direction De pending on the parameter Shape it may be bound to Rows Slant ECC 200 only Using this parameter slanted data codes up to the specified degree can still be read by internally rectifying the image 0 Shape ECC 200 only Data matrix codes are allowed in two different shapes Rect angle and Square The parameter refers to the shape of the data code itself not the shape of the modules Using this parameter you can restrict the data code reader to a specific shape Set to Any if both variants should be detected Setting this parameter to Square will bind both Rows and Columns together so that moving one of the sliders will update the other one accordingly Type QR Code only There are two different models variations of QR Code data codes This parameter specifies the model types that will be detected B A11 Position Patterns present QR Code only QR Codes boast three position finder patterns Use this parameter to control whe
32. gine setting the words of this paragraph in one single line It would make this manual appear rather bulky Because bar codes that encode a lot of information tend to get rather big as well it occurred to some people that they could just as well cut this strip of information into pieces of equal size and stack them up line by line Data codes following this approach are called stacked codes ActivDataCode Supported Data Code Types ActivDataCode supports both matrix and stacked data codes In the former category both Data Matrix ECC 200 and OR Code models 1 and 2 data codes are supported In the latter cat egory the PDF417 Portable Data File data code is supported both conventional and com pact truncated Example images of these data code types are shown in figure 1 1 and figure 1 2 start pattern data stop pattern a ola Ed I Figure 1 2 Components of the PDF417 stacked data code ActivVisionTools 3 2 Your Fast Track to Solutions 4 About ActivDataCode Application In most applications ActivDataCode reads data codes automatically without the need to adjust tons of parameters Even if the detection fails in some images a teaching facility will usually optimize the decoding process automatically But even seemingly hopeless images of poor guality may be decoded by applying preprocessing filters to them Detailed descriptions can be found in the following chapters A data code can appear in any position and any
33. ich could be read before may now require an additional training The label of the button will change to Teach Teaching subsequent data codes will widen the parameter range again Thus no teaching results will get lost If you have a large amount of sample images you can instruct ActivDataCode to teach the data codes automatically by checking v Auto Teach In case you are using live images from a camera auto teaching will slow down the application considerably if no data code is present in the image at all e g while you are positioning a new object in the camera view This is because ActivDataCode tries very hard to find at least one data code in each acquired image by widening the parameter set to the extremes In applications like these make sure to acquire triggered images in a setup where you know the image contains a data code ActivDataCode 2008 04 23 2 3 Teaching Data Codes 13 O single click through image sequence until a 2 let ActivDataCode detect the data code is displayed that cannot be decoded displayed data code 2101 r General Type Data Matrix ECC 200 z Maximum Number of Symbols 1 m Parameters Detect and Teach Auto Teach Reset Details Load Status Not found Save r Acquisition Interface r Display Fe Name Detect Refresh IV Code IV Region 3 L IV Modules 7 Zero
34. isplayModes by clicking on AVTView with the right mouse button and selecting Display Modes in the popup menu Change the color of the selected pick point Select another pick point by clicking into its vicinity Change the color of the currently selected ROI Select another ROI by clicking into its vicinity Change the color of the other not selected ROIs of the currently selected tool Change the color of the ROIs of the other not selected tools Select another tool in the combo box ActivVisionTool of AVTViewROI if this box contains more than one item If you use ActivDecision to evaluate results it can mark ROIs evaluated as not okay in a special color Change the LUT look up table that is used to display the image Change the line width of the ROIs or of the modules or the region margin see below Change the color of the modules and candidates in the text box Group 1 or the color of the zero modules and the region text box Group II ActivDecision uses a separate color to mark objects evaluated as not okay Besides this a further color is used for highlighting objects if you click on them in ActivData View or in the tree of ActivDecision To test the effect open ActivDataView by clicking on AVTDataCode with the right mouse button and selecting Data View in the ap ActivDataCode 2008 04 23 4 1 Adapting the Display of Results 37 OOOO Adapting the Display of ROIs and Results
35. ith the right mouse button and select Zoom from the menu The example below shows a data code with a high contrast Contrast Scaling Row 97 Pixel 100 f b Scaling Row 65 Pixel Gray Value 46 Column 448 Pixel 26 Gray Value 253 Column 451 Pixel b background f foreground The image loaded in the example project has a very bad contrast Thus the Contrast value has to be decreased considerably Watch the visualization of the candidates while pulling the slider to the lowest value Polarity This parameter specifies if data codes appear positive Dark on Light or inverted Light on Dark Set to Any if both variants should be detected The polarity can be determined by looking at the finder pattern In the example image the polarity is Light on Dark Change the parameter accordingly The data code will now be decoded Mirrored This parameter specifies whether data codes may appear mirrored Set to Any if both variants occur or if you are uncertain about the appearance of the actual data code It is sometimes hard to tell just by looking at the data code ActivDataCode 2008 04 23 2 4 Tuning Image Processing 17 General Contrast Min m LL EMC Polarity Current Default Dark on Light X Dark on Light Mirrored Current Default Any sd Any A Contrast L smaller default higher ActivDataCode 6 Polarity E a Dark on Light Light on Dark s m E 7 Mirrored t No Yes Figure 2 5 Tunin
36. larity is inverted which is something the data code reader must be able to deal with From what has been said before it should be clear why data codes are also frequently called 2D bar codes The fact that bar codes are also printed in two dimensions should not confuse you The vertical dimension is only used for redundancy the encoded information in this direction is identical While most of the modules of a matrix data code do encode the actual data there are some modules that invariably appear at the same position in any data code of the same type They ActivDataCode 2008 04 23 1 1 Introducing ActivDataCode 3 Quiet Zone El Finder Pattern HI Modules Data Matrix ECC 200 QR Code E Zero Modules Figure 1 1 Components of the supported matrix data codes build a specific pattern which makes it easy to find the data code in an image Once detected they uniquely determine the orientation of the data code and act as the reference anchor for the data section This static pattern is called finder pattern Apart from the finder pattern a data code is required to be surrounded by a uniform region to simplify its detection and to keep background noise from disturbing the decoding This uniform region is called quiet zone There are also hybrid types of data codes which are composed of multiple bar codes with the addition of efficient error correction and enclosed by start and stop patterns Ima
37. lib The main idea behind AVTViewCalibration is that the user draws a line in the image and tells ActivVisionTools the length of this line in a certain unit From this information AVTViewCali bration calculates the size of a pixel i e its height as square pixels are assumed in this unit which in its turn can be used to convert measurements from pixels into the new unit Note that this conversion only works if the observed objects lie in the same plane i e at the same distance from the camera as the line whose length was specified Preparation for the following example If you worked on the example in the previous chapter you may continue using this project At design time add AVTViewROI AVTViewCalibration and AVTData View to the form by double clicking E4 FZ and FFA with the left mouse button Otherwise open the project unitsNdatacode units vbp Execute the application and open AVTViewFG by clicking into AVTView with the right mouse button and selecting Image Acguisition Load the image seguence datacode ecc200 ecc200_teach seq The following steps are visualized in figure 3 1 not shown AVTDataCode O You create the line of known length using AVTViewROI First select AVTViewCalibra tion1 in the combo box ActivVisionTool To start creating the line click 4 To draw the line move the mouse in the image while keeping the left mouse button pressed You can edit
38. lts override tool defaults and individual conditions override defaults If you check v Substitute Default the entries marked Default are substituted by their actual content ActivVisionTools 3 2 Your Fast Track to Solutions 3 Lo e oO y S a E lt 32 Combining ActivDataCode with other ActivVisionTools Visual Basic Example 3 3 Output of Results Using Using ActivFile you can write the results and the evaluations to a log file How to access results via the programming interface is described in section 4 3 on page 40 how to output them via a serial interface or a digital I O board in the User s Manual for ActivSerial and the User s Manual for ActivDigitallO respectively Preparation for the following example If you worked on the previous example you may continue using this project At design time add AVTOutputFile by double clicking d Otherwise open the project outputNdatacode output vbp Execute the application and load the image sequence data code ecc200 ecc200_capsules seq The following steps are visualized in figure 3 3 not shown AVTView AVTDataCode AVT Decision Q By clicking on Select you can open a file selector box to choose a file name for the log file which will then appear in the text field beside the button By pressing Clear File you can clear th
39. main If Then Else clause around the display of results of the data code extraction now tests the overall evaluation of AVTDataCode1 If atDataCodeResult Evaluation True Then access and display data code extraction results Else examine cause of error more closely End If In the example application the only cause for AVTDataCode1 being evaluated as not okay is that its one ROI has been evaluated as not okay This in turn can have two possible reasons First that the wrong number of objects has been extracted 1 e less or more than one In this case the following code fragment displays a corresponding message in a list box that indicates how many objects have been extracted ActivDataCode 2008 04 23 4 3 Accessing Results Via the Programming Interface 49 If atROIResult FeatureEvaluation handleObjectsInROI False Then sErrMsg Cycle 4 iNumCycles amp wrong number of objects _ atROIResult Value handleObjectsInROI amp Call DisplayMessage sErrMsg End If The error message also contains the number of the cycle in which the error occurred The corresponding counter is incremented in the handler for AVTView s event CycleStart which was introduced already in the previous section Private iNumCycles As Integer Private Sub AVTView1 CycleStart iNumCycles iNumCycles 1 End Sub A second cause of error is that an object has been evaluated as not okay Again a correspond ing e
40. n IV Print Growth IV Grades AVTDataCodeSettings Process Control IV Enable Update AVTDataCodeView Figure A 1 Process control features the distinct process control features are introduced Make sure to check v quality grades of the features as well as the overall quality grade of the data code A 5 1 Symbol Contrast Unit Pixel Grades to get the This feature tests whether modules and zero modules i e dark and light regions of the data code are sufficiently distinct It does this by calculating the difference of the highest and the lowest reflectance values See ISO IEC 15415 for more information on reflectance values Check v Symbol Contrast to calculate this feature Symbol Contrast Grade gt 0 70 70 A gt 0 55 55 B gt 0 40 40 C gt 0 20 20 D lt 0 20 20 F Table A 1 Symbol Contrast grading A 5 2 Slant This feature quantifies the slantedness of a data code in degrees Even though the grading is very strict ActivDataCode can read data codes that are slanted up to 30 Check y Slant to calculate this feature ActivDataCode 2008 04 23 A 5 Available Features 55 Slant in Grade lt 3 50 A lt 4 65 B lt 5 80 C lt 7 00 D gt 7 00 F Table A 2 Slant grading A 5 3 Unused Error Correction This feature quantifies the rese
41. n If you start the continuous mode the cogwheels rotate any interaction on your part is stored in the event queue and processed after the current cycle is finished If ActivDataCode 2008 04 23 4 2 Configuring the Two Execution Modes 39 5 current execution mode 6 processing time or speed O 3 execute a single cycle or start stop the application Gi open the sub tools via the context menu of AVTView O switch between the two modes select what is to be displayed and whether ROls can be edited w Switching Between the Two User Modes ris 1 106 3 ms Loading file g hd 01 iyi Execution f Display Image I Display ROIs f Allow ROI editing f Display Results IV Display Error Results f Allow Drag amp Drop r Configuration Mode IZ Display Image IV Display ROIs IZ Allow ROI editing IV Display Results IV Display Error Results IV Allow Drag Drop 7 space for messages Figure 4 2 Customizing and switching between the two execution modes the cursor gets busy ActivVisionTools has started a particularly time consuming op eration e g connecting to an image acquisition device Any interaction on your part is then deferred to the end of this operation AVTViewStatus also shows the number of processed cycles and the time needed for the last processing cycle AVTViewStatu
42. n ROI can be accessed by specifying its name in a call to the method ROIResult or by specifying its index in a call to the method ROTResults The following code uses the latter method to access the first ROI of AVTDataCode1 Dim atROlResult As AVTROIResult Set atROIResult atToolResults ROIResults 0 Now we can e g query the number of objects extracted in the ROI via Dim iNumObjects As Integer iNumObjects atROlResult ObjectNum Actual results for an object i e the extracted code or the calculated position can be accessed by specifying the feature of interest and the ID of the object in a call to the method ObjectValue of ACTIVVTOOLSLib AVTROIResult The feature handles are available as methods of the cor responding tool e g AVTDataCode FeatureHandleCode being the handle for the extracted code The following code fragment uses another method of ACTIVVTOOLSLib AVTROIResult Ob jectValues which returns the values of all objects for the specified feature in an array to calculate the mean unused error correction of the data codes Dim handleUEC As Integer i As Integer Dim vUECArray As Variant Dim dSumUEC As Double dMeanUEC As Double handleUEC AVTDataCode1 FeatureHandleUnusedErrorCorrection vUECArray atROlIResult ObjectValues handleUEC dSumUEC 0 For i 0 To iNumObjects 1 dSumUEC dSumUEC vUECArray i Next dMeanUEC dSumUEC iNumObjects As already noted in Visual Basic NET tool names are prefixed with Ax th
43. n now calculates the height of a pixel in the selected unit and displays it in the text box Pixel Height D Automatically the data code position is converted into the selected unit ActivVisionTools 3 2 Your Fast Track to Solutions 30 Combining ActivDataCode with other ActivVisionTools Visual Basic Example 3 2 Evaluating Results Using B In the former examples you have employed Activ VisionTools to extract and display data codes and additional features Using ActivDecision you can evaluate these results by formulating conditions the results have to meet in order to be okay For a detailed description of Activ Decision please consult the User s Manual for ActivDecision Preparation for the following example If you worked on the previous example you may continue using this project At design time add AVTDecision to the form by double clicking ES with the left mouse button delete AVTDataView AVTViewCalibration and AVTViewROI Otherwise open the project decisions datacode_decisions vbp Execute the application and load the image sequence data code qrcode qr_hd seq The following steps are visualized in figure 3 2 not shown AVTView and AVTDataCode G The main functionality of ActivDecision is presented by its support tools which can be opened via clicking on AVTDecision with the right mouse button The master tool displays the overall evalua
44. ngle parameter values Specifically make sure to check v Candidates because this will highlight image areas that are considered to potentially contain data codes of the selected type G Click the Details button to open the parameter dialog Alternatively you can add AVTDataCodeParameters E to the form at design time The default settings dis played in this dialog depend on the selected data code type Some parameters are not available for all supported data codes The corresponding parameters will be grayed out in the dialog 4 Some parameter values can be changed by moving sliders If both a minimum and a maximum value can be specified two linked sliders are available You can also specify the values explicitly by editing the text boxes Using the arrow buttons the values can be decremented or incremented Other parameters can be specified by selecting from a combo box When you change a parameter value the current image is searched again ActivDataCode 2008 04 23 2 4 Tuning Image Processing 15 O make sure the default settings are used 2 visualize all data code components in image view i Tuning Data Code Reader Jia lt l j x x General Contrast Min DS Palio p Polarity Current Default Dark on Light fad Dark on Light Mirrored Current Default any Any
45. on one has to keep in mind that AVTDataCode is executed not only when the next image is grabbed but also whenever you modify its ROI s or parameters To distinguish the two cases an event raised by AVTView at the start of each execution cycle can be used to set a flag called bIsNewCycle Private bIsNewCycle As Boolean Private Sub AVTView1 CycleStart bIsNewCycle True End Sub Before calculating the mean values within the handler for AVTDataCode s event Finish this variable is checked and immediately reset ActivDataCode 2008 04 23 4 3 Accessing Results Via the Programming Interface 45 If bIsNewCycle True Then iNumGoodCycles iNumGoodCycles 1 bIsNewCycle False dSumUEC dSumUEC dUEC dMeanUEC dSumUEC iNumGoodCycles LabelUEC Caption Format dMeanUEC Fixed End If You can test this behavior by changing parameters in AVTDataCodeParameters The code is updated while the mean value of the unused error correction remains constant When using the programming interface of ActivVisionTools you leave the safe world of the graphical user interfaces where all input is checked for validity automatically In contrast if you try to access a non existent object or result via the programming interface a run time error is caused which terminates your application To avoid this you can use the Visual Basic error handling mechanisms i e set up an error handler which examines any occurring error and reacts in a suitabl
46. orientation Furthermore data code extraction with ActivDataCode is very robust It extracts data codes even from difficult backgrounds and in case of varying illumination ActivDataCode can also be instructed to read several data codes at once from the same image provided they are of the same type To speed up the extraction you can specify regions of interest ROIs By default ActivDataCode will offer to create an ROI that covers the entire image If you want to decode data codes of different type in the same application you will have to add multiple ActivDataCode tools Results The result of ActivDataCode is of course the content of the extracted data code Furthermore ActivDataCode lets you output additional information also called features e g the position of the data code in the image see figure 1 3 the appearance or the actual sub type of the data code You can also request results concerning the print quality of the data code see appendix A on page 51 for more information The results of ActivDataCode can be further evaluated using ActivDecision before you output them via ActivFile ActivSerial or ActivDigitallO further more you can access results via the programming interface see section 4 3 on page 40 Column Figure 1 3 The position of a data code in the image ActivDataCode 2008 04 23 1 2 The Sub Tools of ActivDataCode 5 1 2 The Sub Tools of ActivDataCode Besides its master tool ActivDat
47. ou worked on the example in the previous chapter you may continue using this project At design time add AVTViewExecuteSimple and AVTViewStatus to the form by double clicking the icons Br and Ai with the left mouse button Otherwise open the project usermodes datacode_usermodes vbp Execute the application and load the sequence datacode qrcode qr_hd seq The following steps are visualized in figure 4 2 not shown AVTDataCode O Open AVTViewExecute and AVTViewConfigExec by clicking on AVTView with the right mouse button and selecting Execution and Execution Parameters 2 Switch between the two execution modes via AVTViewExecute s combo box Mode To execute one cycle press Single With the other two buttons you can let the appli cation run continuously and stop it again By default AVTViewExecuteSimple starts and stops an application how to change its behavior to a single step button is described in the User s Manual for Activ View section 3 4 on page 34 4 For each of the two execution modes you can choose what is to be displayed by check ing the corresponding boxes in AVTViewConfigExec Furthermore you can specify if images can be dragged to the image window and whether ROIs can be modified in the two modes 6 In AVTViewStatus an icon indicates the current execution mode of the application In the mode the application does not perform any processing and waits for your interactio
48. play 3 enable Auto Teach 4 enable image preprocessing 5 visualize preprocessing results Figure 2 8 Preprocessing the image We continue with the example on the next double page ActivVisionTools 3 2 Your Fast Track to Solutions 24 Using ActivDataCode Preprocessing Image Processing continued The following steps are visualized in figure 2 9 6 Smoothing This filter is particularly useful for noisy images Besides it may improve data code detection if the finder pattern of the data code is disturbed e g by lines in the background or foreground D Growth If negative this filter enlarges bright image areas If positive it enlarges dark image areas Itis most useful for data codes of bad print quality If too much ink is used in the printing process the ink tends to bleed in the surrounding area causing a so called print growth If too few ink is used the modules may become frayed or full of holes By adjusting the Growth value accordingly these deficiencies can be compensated Contrast This filter enhances the contrast of the image It may improve data code detection in low contrast images 9 v Compensate for Low Resolution The data code expects the modules to have a specific minimum size Enabling this filter will improve detection of data codes with very small module sizes ActivDataCode 2008 04 23 2 5 Preprocessing Images 25 6 Smoothing off high 7 Growth
49. r Display Region of Interest Men z uu Red y Error ROI Selected Tool i Yellow Inactive Tools Gray Special Magenta Pick Point O Red z Line Width 1 Pixel y r Display Image LUT E defaut 7 7 Text Background SN cinta Contburs r Display Results Group Group II I Green Error Rea Selected Yellow Display Mode Filled Line Width 1 Pixel Te Wee A MS Sans Serf 12pt J O open AVTViewDisplayModes via a click on AVTView with the right mouse button ioj xi General Type QR Code Es Maximum Number of Symbols po m Parameters Detect and Teach Auto Teach Reset Details Load Save Status Not found Display IZ Code IV Region IZ Modules IV Zero Modules IV Candidates IF Preprocessing 3 Results 6 IV Code IV Type Information Q IZ Position I Appearance 5 X Process Control a T Symbol Contrast J Axial Nonuniformity 3 TT Slant f Grid Nonuniformity lt f Unused Error Correction T Print Growth f Grades color of the selected pick point color of the different types of ROIs look up tables for image display line width of the ROIs or of the modules and the region contour color of the modules and candidates Group I color of the zero modules and region Group 7 color of results that are not okay or of selected results color fon
50. rary L Acrobat Priority C Acrobat Access 2 0 Type Library C Acrobat Access 3 0 Type Library D acrobat Distiller C Acrobat WebCapture 1 0 Type Library Acrobat WebCapture IE Toolbar Favorites 1 0 Type L crolEHeloer 1 0 Type Library ActivVisionTools 3 1 Type Library Location C Program Files MYTeclActivVisionTools bintiS86 nt4 ActivYTi Language Standard ActivDataCode 2008 04 23 4 3 Accessing Results Via the Programming Interface 41 4 3 1 Accessing the Results of Data Code Extraction The principal idea behind accessing the results of an ActivVisionTool is guite simple When a tool has finished its execution it raises an event called Finish sending its results as a parameter If you want to access the results all you have to do therefore is to create a corresponding event procedure which handles the event Within the Visual Basic environment you can create event procedures very easily as shown in figure 4 3 In the header of the form s code window corresponding to a form there are two combo boxes Select the instance of AVTDataCode by default called AVTDataCode1 in the left combo box The right combo box then lists all events available for this object when you select Finish the event procedure is created automatically Within this procedure the results of the data code extraction are now accessible via the object variable atToolResults Fa ResultAccess datacode_resultaccess Code i ol xj
51. ries to find a data code of the currently selected type inside it The default setting of ActivDataCode is to look for ECC 200 data codes Using AVTDataCode you can setup the data code type of your application With AVTDataCodeSettings you can configure the output behavior of ActivDataCode Preparation for the following example If you worked on the previous example you may continue using this project At design time add AVTViewStatus AVTDataCodeSettings and AVTDataView by double clicking Hi E and HE You may delete AVTViewROI as it can be opened at run time by clicking into AVTView with the right mouse button and select ing Region of Interest Otherwise open the project reading datacode_reading vbp Execute the application Run gt Start or via the corresponding button and open AVTViewFG by clicking into AVTView with the right mouse button and selecting Image Acquisition in the popup menu Select the image data code qrcode qr_hd_01 in the combo box Input File The following steps are visualized in figure 2 2 Specify the data code type in the combo box Type In the example image a QR Code is displayed If you do not know the type of the data code you can look up the supported data codes in figure 1 1 on page 3 The supported data codes can be distinguished easily by looking at the finder pattern If the ROI is correctly placed around the data code including the quiet zone
52. rror message is created this time containing the extracted data code The following code shows how to access the indices of all objects evaluated as not okay Dim badObject As Variant If atROIResult FeatureEvaluation handleBadObjectsInROI False Then gt get all bad objects cause bad code For Each badObject In atROIResult BadObjectIndices sErrMsg Cycle amp iNumCycles object badObject amp _ has wrong code amp _ atROIResult ObjectValue handleCode badObject amp Call DisplayMessage sErrMsg Next End If ActivVisionTools 3 2 Your Fast Track to Solutions ActivDataCode 50 Tips amp Tricks ActivDataCode 2008 04 23 Appendix A Process Control Features ActivDataCode This appendix is a short introduction to the process control features of ActivDataCode Ad Introduccion a ak ak k a k k 52 A 2 Data Code Production bk 52 A 3 International Standards bk ee eee eee ee ee eee 53 Ad Quality Grades sce s a s eee ee ee ee 53 AS Available Features VL 53 ASL Symbol Contrast ooo k ee Ba eS 54 Ae a TTT T TTT 54 Ads Unused Error Correction k ads e ee RS 55 ASA Axial Nono cepo k k 55 AS 3 Grid Noniniiormity s 64 55 4204 606 Soe ra E 56 AM Print Growth se e caat eu ee ee ea E 56 51 52 Process Control Features A 1 Introduction The focus of the main part of this manual is about setting up and using ActivDataCode to read data codes in produ
53. rs of ActivDataCode If however auto teaching fails simply because the properties of a data code lie outside of the search range you can try to adjust the parameters manually On the other hand if the data code could be read but you want to know the detailed changes of a specific training step you can also take a look at the parameter dialog Reversely you can explicitly set the parameters to certain known values and test a range of data codes for compliance You can always return to the default settings at the click of a button ans Preparation for the following example Example If you worked on the previous example you may continue using this project Otherwise open the project tuning datacode_tuning vbp Execute the application Run gt Start or via the corresponding button and load the image datacode ecc200 ecc200_tune_04 Open AVTViewROI by selecting Re gion of Interest in the popup menu and place an ROI over the data code Click Detect and Teach in AVTDataCode You will get a message saying that no data code could be detected in the image The following steps are visualized in figure 2 4 O Click the Reset button to set all the parameters to their default values i e any training information will be lost 2 Select all check boxes in the Display frame of AVTDataCodeSettings This will help you to see the changes to the decoding process while you are changing si
54. rve in error correction that is still available after decoding the data code A perfect data code requires no error correction at all resulting in a value of 1 0 for this feature The more defective a data code becomes the more the inherent error correction o needs to be applied to still be able to decode the data code Please note that ActivDataCode only 3 evaluates the total error correction capacity For large codes with multiple independent error Q correction blocks this is only an approximation a Check v Unused Error Correction to calculate this feature O lt Unused Error Correction Grade gt 0 62 A gt 0 50 B gt 0 37 C 2 0 25 D lt 0 25 F Table A 3 Unused Error Correction grading A 5 4 Axial Nonuniformity This feature evaluates the squareness of the data modules Ultimately it judges the aspect ratio of the data code resulting in bad quality grades for shrinkage or enlargement in one direction uneven scaling Please note that this feature is not used for PDF417 due to the variable aspect of modules Check v Axial Nonuniformity to calculate this feature ActivVisionTools 3 2 Your Fast Track to Solutions 56 Process Control Features Axial Nonuniformity Grade lt 0 06 A lt 0 08 B lt 0 10 C lt 0 12 D gt 0 12 F Table A 4 Axial Nonuniformity grading A 5 5 Grid Nonuniformity Thi
55. s display two types of messages Informative messages describe e g what the application is doing while it is busy while error messages indicate errors that prevent the application from working correctly e g the failure to detect a data code automatically Note that the failure to find a data code ranks as an information and not as an error i e the application is not interrupted You can use ActivDecision to mark such cases as not okay If AVTViewStatus is not added to an application error messages are displayed in popup dialogs More information about AVTViewStatus e g how to modify its appearance can be found in the User s Manual for ActivView section 3 3 on page 32 ActivVisionTools 3 2 Your Fast Track to Solutions ActivDataCode 40 Tips 8 Tricks o 4 3 Accessing Results Via the Programming Interface The previous chapters and sections showed how to use ActivVisionTools interactively i e via the graphical user interfaces presented by the underlying ActiveX controls In this mode you can develop the image processing part of your machine vision application rapidly and easily without any programming However there is more to ActivVisionTools than the graphical user interfaces Because ActivVisionTools comes as a set of ActiveX controls it provides you with an open programming interface thereby offering full flexibility In this section we show how to access the results of the data
56. s feature quantifies the deviation of the modules of the data code from their ideal grid How ever a bad value might also be caused by problems with the finder pattern in which case the ideal grid may not be positioned correctly Check v Grid Nonuniformity to calculate this feature Grid Nonuniformity Grade lt 0 38 A lt 0 50 B lt 0 63 C lt 0 75 D gt 0 75 F Table A 5 Grid Nonuniformity grading A 5 6 Print Growth This feature guantifies the uniformity of dark and light module sizes i e how appropriately the modules fill their module boundaries Depending on the print process of the data code the desired module size may be affected For example in ink jet printing the ink may bleed into the surrounding area causing the background modules to shrink The values are calculated for both horizontal and vertical module sizes hence Print Growth X and Print Growth Y are reported The value 0 0 correlates to a module size of 100 Negative values denote module shrinkage while positive values denote module growth A quality grade is not calculated for this feature Check v Print Growth to calculate this feature ActivDataCode 2008 04 23
57. sult FeatureEvaluation handleObjectsInROI The ActivVisionTools distribution includes the example Visual Basic project evalac cess datacode_evalaccess vbp which uses these methods to extend the application de scribed in the previous section Now ActivDecision is used to check the extracted data code as described in section 3 2 on page 30 in case the overall evaluation shows an error the cause of the error is displayed see figure 4 5 The example project is already configured just start it and click the button Run in AVTViewExecute ActivVisionTools 3 2 Your Fast Track to Solutions ActivDataCode 48 Tips 8 Tricks Accessing the Results via the Programming Interface Oj xj r General Type or Code y Maximum Number of Symbols fe m Parameters Teach FF Auto Teach Reset Details Load Save Status OK a I 4 AT Current Code Mean UEC Execution Application v Mode T Execute Slaves Cycle 8 wrong number of objects 2 Single Run Stop Cycle 8 object O has wrong code OS Cycle 10 object O has wrong code HD 7 Figure 4 5 Accessing and displaying the evaluation results Besides accessing the evaluation results the project code contains additional functionality which is explained briefly in the following again only for Visual Basic 6 0 First of all the
58. t and background of text 9 drawing mode for regions and contours Figure 4 1 Adapting the display of ROIs and results pearing context menu then click on a object which is automatically highlighted in AVTView Change the color and the font of the text and whether it is displayed on a contrasting background Change the way modules are displayed filled or margin and whether contours and text are framed with a contrasting color to make them more visible against busy backgrounds ActivVisionTools 3 2 Your Fast Track to Solutions 38 Tips 8 Tricks 4 2 Configuring the Two Execution Modes Via and H In an ActivVisionTools application you can switch between two execution modes the config uration mode and the application mode The former should be used to setup and configure an application the latter to run it ActivView s support tools AVTViewExecute and AVTView ConfigExec allow you to switch between the two modes and to customize the behavior of an ActivVisionTools application in the two execution modes e g display live images only in the configuration mode to setup your application but then switch it off in the application mode to speed up the application A third sub tool AVTViewExecuteSimple provides a single button to start stop the application In this section we also describe AVTViewStatus in more detail isual Basi f Vishal Basic Preparation for the following example Example If y
59. ted with ActivVisionTools For each example in this manual there is a corresponding Visual Basic project these projects can be found in the subdirectory exam ples manuals activdatacode of the ActivVisionTools base directory you selected during the installation default C Program Files MVTec ActivVisionTools Of course you can also create your own Visual Basic projects from scratch We recommend to create a private copy of the example projects because by experimenting with the projects you also change their state which is then automatically stored in the so called description files extension dsc by ActivVisionTools Of course you can restore the state of a project by retrieving the corresponding description file from the CD About ActivDataCode 1 1 Introducing ActivDataCode 1 2 The Sub Tools of ActivDataCode Using ActivDataCode 2 1 Specifying Regions of Interest 22 Reading Dala Codes Luka k Res 2 3 Teaching Data Codes c oe cest oro 2 4 Tuning Image Processing 2 Preprocessing MAZES oo cc rs Combining ActivDataCode with other ActivVisionTools 3 1 Converting Results to Other Units 3 2 Evaluating Results 23 Dutputal Results ocasione k pe Tips amp Tricks 4 1 Adapting the Display of Results 4 2 Configuring the Two Execution Modes 4 3 Accessing Results Via the Programming Int
60. ther the data code reader needs to find all three patterns to read the data code or if two patterns suffice to start the decoding process ActivDataCode 2008 04 23 2 4 Tuning Image Processing 19 Symbol Rows Rows Min Max A le el dra e Columns Min Max A fio A alfa pl Slant Mas ao gt Shape Current Default Any y Any Columns T Current Default Eu Al nsp Slant n HE 4d Shape t ActivDataCode Sguare Rectangle 2 Type QR Code Model QR Code Model 2 OFF m 43 Need all Position Patterns A Extension Patterns except Version 1 Alignment Pattern except Version 1 Fourth Corner is Fixed Figure 2 6 Tuning image processing parameters cont We continue with the example on the next double page ActivVisionTools 3 2 Your Fast Track to Solutions 20 Using ActivDataCode Tuning Image Processing continued The following steps are visualized in figure 2 7 on page 21 Size This parameter specifies a valid range of pixel sizes for the modules Data codes with module sizes outside of this range will not be detected 5 Aspect PDF417 only In PDF417 data codes the height and the width of the modules may differ Using this parameter you can specify the valid range of aspect ratios Gap ECC 200 and QR Code only Depending on the printing or embossing method there may be gaps between the single modules of a data code Using this parameter you
61. tion of the application To view the current feature and evaluation results check v Enable Update in AVT DecisionViewResults ActivDecision lets you compare the value of an individual object ROI or tool feature with two boundary values a minimum and a maximum value In the image sequence two different data codes appear HD 7100 080GB and HD 7100 160GB only the latter is to be evaluated as okay In the columns Min and Max change the minimum and maximum values for the feature Data accordingly Now select a condition that the result has to meet in the column Operation In our example the Data has to be equal to the Max value If you select None the result is not evaluated Those features which meet their condition appear in green the others in red If at least one feature is not okay the whole object ROL or tool is evaluated as not okay as well Analogously the overall evaluation of the application which is visualized by AVTDecision depends on the tool evaluations Figure 3 2 shows suitable conditions for the example task Step through the image se guence by clicking Single in AVTViewFG and examine the evaluations Experiment by formulating additional conditions e g regarding the position or orientation of the data codes ActivDataCode 2008 04 23 3 2 Evaluating Results 31 j O open the support tools via the context menu right mouse click ROls or tools 2 enable the upd
62. to finish i e create the event procedure Private Sub AVTDecisioni_Finish atToolResults As Collection End Sub Note that you will get a run time error if you try to access evaluation results before Activ Decision has finished e g in the handler for AVTDataCode s event Finish Because ActivDecision can evaluate the results of more than one tool the event handler provides you with a Collection of tool results The following code fragment searches the collection for the results of AVTDataCode1 and stores them in atDataCodeResult or exits if no results are found Dim atToolResult As AVTToolResult Dim atDataCodeResult As AVTToolResult Dim bDataCodeResultsFound As Boolean bDataCodeResultsFound False For Each atToolResult In atToolResults If atToolResult Name AVTDataCodei Then Set atDataCodeResult atToolResult bDataCodeResultsFound True End If Next If bDataCodeResultsFound False Then Exit Sub End If In Visual Basic NET the event procedure has the following signature Private Sub AxAVTDecisioni_Finish ByVal sender As Object _ ByVal e As _ AxActivVTools __AVTDecision_FinishEvent _ Handles AxAVTDecision1 Finish Again the tool results are encapsulated in the parameter e They can be extracted as follows ActivDataCode 2008 04 23 4 3 Accessing Results Via the Programming Interface 47 note the use of VBA Collection instead of Collection Dim atToolResults As VBA Collection atToolResults e
63. until the detection succeeds This is referred to as teaching a data code The taught parameters can be saved to disk for later use How to use AVTDataCode is described in more detail in section 2 2 on page 10 ActivVisionTools 3 2 Your Fast Track to Solutions 6 About ActivDataCode EG AYTDataCodeParameters x ia AVTDataCodePreprocessing r General Contrast Min AH AVTDataCodeParameters alo e Polarity Current Default iol x Dark on Light y Dark on Light r General Mirrored Current Default 7 Data Mati ECO 200 Aro a Ew ype ata Matrix Maximum Number of Symbols fi r Symbol Rows Min m Parameters a 45 gt aff La gt Teach Auto Teach Columns Min Reset Load NAAA Ufo gt af 144 T gt Details Save Slant ax Status OK a Oi no l Shape Current Default Es Rectangle y Any IZ Cod Type Current Default IZ Modules P 2 E reprocessing 142 y I Candidates BB Smoothing 4 fo l 7 Need all Position Patterns r Results Growth A A fo E V Code p Module 7 Position Contrast ajf Ho E Size Min L Compensate for Low Resolution le gt tice mr m Process Control Aspect Min Max 7 Symbol Contra IV Apply Preprocessing ve lh 0 gt E 40 gt T Slant fonuniormity f Unused Error Correction Current Default Rado T Grad Ire or Small No or
64. us the feature handle is accessed as follows handleUEC AxAVTDataCode1 FeatureHandleUnusedErrorCorrection ActivDataCode 2008 04 23 4 3 Accessing Results Via the Programming Interface 43 i Accessing the Results via the Programming Interface jol xj r General Type or Code Maximum Number of Symbols fe m Parameters Teach f Auto Teach Reset Details Load Save Status OK Current Code HD 7100 160GB Mean UEC r Executi xecution Large HDs Small HDs a lication Mode sa TF Execute Slaves Figure 4 4 Accessing and displaying the results of data code extraction The ActivVisionTools distribution includes the example Visual Basic project resultac cess datacode_resultaccess vbp which uses the methods described above to extend the application for reading a sequence of data codes introduced in the previous chapter The task is to display the extracted code which identifies hard disks of different sizes Depending on the hard disk size counters for large and small hard disks are updated To control the overall quality of the data codes the mean value of the Grade UEC unused error correction feature is also calculated The higher the displayed value the better the overall quality of the data codes see figure 4 4 The example project is already configured just start it and click the button Run in AV
65. w to customize the appearance of an Activ DataCode application in the two execution modes Furthermore it shows how to access data code extraction and evaluation results directly via the programming interface of the ActivVision Tools 4 1 4 2 4 3 Adapting the Display of Results o o 36 Configuring the Two Execution Modes 38 Accessing Results Via the Programming Interface 40 4 3 1 Results of Data Code Extraction 2 41 432 Expluati on Results o e ea ce wa bh eH REDS OAR DEO 46 35 ActivDataCode 36 Tips 8 Tricks Visual Basic Example 4 1 Adapting the Display of Results Using a You can adapt the way results and ROIs are displayed using AVTViewDisplayModes which is a support tool of ActivView Preparation for the following example If you worked on the example in the previous chapter you may continue using this project Otherwise open the project display datacode_display vbp and execute it Run gt Start or via the corresponding button Load the image sequence datacode qrcode qr_hd seq and create some addi tional ROls AVTViewFG and AVTViewROI can be opened at run time via a right mouse button click on AVTView The following steps are visualized in figure 4 1 Experiment by choosing different settings for the display parameters and watching the result O 0060 Open AVTViewD

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