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OcrOmrFrameDetectionMethod Enumeration

The OMR frame detection mode.
public enum OcrOmrFrameDetectionMethod   
typedef NS_ENUM(NSInteger, LTOcrOmrFrameDetectionMethod) { 
 LTOcrOmrFrameDetectionMethodAuto = 0,  
 LTOcrOmrFrameDetectionMethodLast = LTOcrOmrFrameDetectionMethodWithFrame 
public enum OcrOmrFrameDetectionMethod 
public enum class OcrOmrFrameDetectionMethod   
class OcrOmrFrameDetectionMethod(Enum): 
   Auto = 0 
   WithoutFrame = 1 
   WithFrame = 2 
0Auto Automatically detect whether there is a printed frame (e.g. check box).
1WithoutFrame The OMR zone is inside the printed frame, so the printed frame is not visible.
2WithFrame The OMR zone is outside the printed frame, so the printed frame is visible.

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

Frames stand for the check boxes that may exist around OMR fields. You can set the LEADTOOLS OCR engine to automatically detect these frames and take them into consideration when recognizing OMR fields. If you know whether the OMR fields contain frames, set the IOcrOmrOptions.FrameDetectionMethod accordingly to increase recognition performance and accuracy.

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.