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OmrState Property

Gets or sets the after-recognition state of the OMR mark if this is an OMR zone.
public OcrOmrZoneState OmrState { get; set; } 
public OcrOmrZoneState getOmrState() 
public void setOmrState(OcrOmrZoneState value) 
property OcrOmrZoneState OmrState { 
   OcrOmrZoneState get(); 
   void set (    OcrOmrZoneState ); 
OmrState # get and set (NativeOcrZone) 

Property Value

One or more OcrOmrZoneState enumeration member that indicate the after-recognition state (filled or unfilled) of the mark of this zone.


OMR stands for Optical Mark Recognition. For more information refer to Using OMR in LEADTOOLS .NET OCR.

After IOcrPage.Recognize is called, all the OMR zones in the page will have the OMR properties updated as follows:

Property Description
NativeOcrZone.OmrState Either OcrOmrZoneState.Filled if the mark is recognized to be filled or checked, or OcrOmrZoneState.Unfilled if the mark is recognized to be unfilled or unchecked.
NativeOcrZone.OmrConfidence A number between 0 and 100 (where 100 is maximum confidence) that specifies the OCR engine confidence in the recognition status in NativeOcrZone.OmrState.

The OMR zones of a page are zones with the following properties:

Property Value
NativeOcrZone.FillMethod Set to NativeOcrZoneFillMethod.Omr.
NativeOcrZone.RecognitionModule Set to NativeOcrZoneRecognitionModule.Omr.

All LEADTOOLS OCR engines support OMR. However, there isn't any current support for auto-detecting OMR zones in a page. To do that, add the OMR zones manually to the page by setting their boundary (through NativeOcrZone.Bounds, the fill method and recognition module as described above and adding the zone to the page using the IOcrPage.Zones collection before calling IOcrPage.Recognize.

To use OMR in LEADTOOLS, you need a special key to unlock the OMR capabilities. For more information, refer to Unlocking Special LEAD Features.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Ocr; 
using Leadtools.Forms.Common; 
using Leadtools.Document.Writer; 
using Leadtools.WinForms; 
public void OcrOmrExample() 
   // Create an instance of the engine 
   using (IOcrEngine ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD)) 
      // Start the engine using default parameters 
      ocrEngine.Startup(null, null, null, LEAD_VARS.OcrLEADRuntimeDir); 
      // We will use Mixed.tif shipped with LEADTOOLS in the Images folder. This image has 3 OMR check marks 
      string tifFileName = Path.Combine(LEAD_VARS.ImagesDir, "Mixed.tif"); 
      // Create an OCR document 
      using (IOcrDocument ocrDocument = ocrEngine.DocumentManager.CreateDocument()) 
         // Add a page to the document 
         IOcrPage ocrPage = ocrDocument.Pages.AddPage(tifFileName, null); 
         // Add the OMR zones. We calculated the 3 OMR zone boundaries for this image perviously 
         LeadRect[] omrBounds = 
            new LeadRect(484, 98, 84, 78), 
            new LeadRect(494, 184, 70, 54), 
            new LeadRect(498, 244, 76, 76) 
         foreach (LeadRect omrBound in omrBounds) 
            // Create a new OMR zone and add it to the page 
            OcrZone zone = new OcrZone(); 
            zone.ZoneType = OcrZoneType.Omr; 
            zone.Bounds = omrBound; 
         // Show how many zones we have and they properties 
         Console.WriteLine("Page has {0} zones:", ocrPage.Zones.Count); 
         for (int i = 0; i < ocrPage.Zones.Count; i++) 
            OcrZone zone = ocrPage.Zones[i]; 
            Console.WriteLine("{0}: Type: {1}", i + 1, zone.ZoneType); 
         // Change the OMR options (Auto detection of frames with highest sensitivity) 
         IOcrOmrOptions omrOptions = ocrEngine.ZoneManager.OmrOptions; 
         omrOptions.FrameDetectionMethod = OcrOmrFrameDetectionMethod.Auto; 
         omrOptions.Sensitivity = OcrOmrSensitivity.Highest; 
         // Get the character we are using in the engine to represent the filled/unfilled states 
         char filledCode = omrOptions.GetStateRecognitionCharacter(OcrOmrZoneState.Filled); 
         char unfilledCode = omrOptions.GetStateRecognitionCharacter(OcrOmrZoneState.Unfilled); 
         // Recognize the page 
         IOcrPageCharacters pageCharacters = ocrPage.GetRecognizedCharacters(); 
         foreach (IOcrZoneCharacters zoneCharacters in pageCharacters) 
            // We must have one character (the state for each OMR zone) 
            Debug.Assert(zoneCharacters.Count == 1); 
            OcrCharacter character = zoneCharacters[0]; 
            Debug.Assert(character.Code == filledCode || character.Code == unfilledCode); 
            Console.WriteLine("{0}: State: {1}, Confidence: {2}", zoneCharacters.ZoneIndex, character.Code == filledCode ? "Filled" : "Unfilled", character.Confidence); 
         // Now save the result as PDF using the default characters representation for OMR states (0 for unfilled, 1 for filled) 
         string pdfFileName1 = Path.Combine(LEAD_VARS.ImagesDir, "Omr_Results1.pdf"); 
         Console.WriteLine("Saving to {0}...", pdfFileName1); 
         ocrDocument.Save(pdfFileName1, DocumentFormat.Pdf, null); 
         // Change the character representation for the OMR states to Y for unfilled, and X for filled 
         omrOptions.SetStateRecognitionCharacter(OcrOmrZoneState.Unfilled, 'Y'); 
         omrOptions.SetStateRecognitionCharacter(OcrOmrZoneState.Filled, 'X'); 
         string pdfFileName2 = Path.Combine(LEAD_VARS.ImagesDir, "Omr_Results2.pdf"); 
         Console.WriteLine("Saving to {0}...", pdfFileName2); 
         ocrDocument.Save(pdfFileName2, DocumentFormat.Pdf, null); 
      // Shutdown the engine 
      // Note: calling Dispose will also automatically shutdown the engine if it has been started 
static class LEAD_VARS 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
   public const string OcrLEADRuntimeDir = @"C:\LEADTOOLS22\Bin\Common\OcrLEADRuntime"; 

Target Platforms

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Leadtools.Ocr Assembly

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© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.