The OMR (Optical Mark Recognition) settings currently used by the engine.
public interface IOcrOmrOptions
Public Interface IOcrOmrOptions
@interface LTOcrOmrOptions : NSObject
public class OcrOmrOptions
public interface class IOcrOmrOptions
Use of OMR in LEADTOOLS requires a special key to unlock OMR capabilities. For more information, refer to Unlocking Special LEAD Features.
To get the instance of the IOcrOmrOptions interface currently used in the engine call the IOcrSpellCheckManager.OmrOptions property.
Use the IOcrOmrOptions interface to change the following OMR settings:
The OMR zones of a page are zones that have the OcrZone.ZoneType set to OcrZoneType.Omr.
All LEADTOOLS OCR engines support OMR. However, only the LEADTOOLS OCR Module - LEAD Engine supports auto-detection of OMR zones during auto-zoning of the OCR page. To set up OMR zone auto-detection, make sure that the "Detect Checkbox" is one of the Recognition.Zoning.Options setting flags included before calling IOcrPage.AutoZone or IOcrPage.Recognize. The rest of the OCR engines require that the OMR zones be manually added to the page by setting their boundaries through OcrZone.Bounds and zone type as described above. Then add the zones to the page using the IOcrPage.Zones collection before calling IOcrPage.Recognize.
For more information refer to Using OMR in LEADTOOLS .NET OCR.
This example will load a TIF image, create OMR zones and recognize them.
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, false))
{
// 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;
ocrPage.Zones.Add(zone);
}
// 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
Console.WriteLine("Recognizing...");
ocrPage.Recognize(null);
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
ocrEngine.Shutdown();
}
}
static class LEAD_VARS
{
public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
public const string OcrLEADRuntimeDir = @"C:\LEADTOOLS 20\Bin\Common\OcrLEADRuntime";
}
Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.Ocr
Imports Leadtools.Forms
Imports Leadtools.Document.Writer
Imports Leadtools.WinForms
Public Sub OcrOmrExample()
' Create an instance of the engine
Using ocrEngine As IOcrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD, False)
' Start the engine using default parameters
ocrEngine.Startup(Nothing, Nothing, Nothing, LEAD_VARS.OcrLEADRuntimeDir)
' We will use Mixed.tif shipped with LEADTOOLS in the Images folder. This image has 3 OMR check marks
Dim tifFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Mixed.tif")
' Create an OCR document
Using ocrDocument As IOcrDocument = ocrEngine.DocumentManager.CreateDocument()
' Add a page to the document
Dim ocrPage As IOcrPage = ocrDocument.Pages.AddPage(tifFileName, Nothing)
' Add the OMR zones. We calculated the 3 OMR zone boundaries for this image perviously
Dim omrBounds As LeadRect() = {
New LeadRect(484, 98, 84, 78),
New LeadRect(494, 184, 70, 54),
New LeadRect(498, 244, 76, 76)}
For Each omrBound As LeadRect In omrBounds
' Create a new OMR zone and add it to the page
Dim zone As New OcrZone()
zone.ZoneType = OcrZoneType.Omr
zone.Bounds = omrBound
ocrPage.Zones.Add(zone)
Next
' Show how many zones we have and they properties
Console.WriteLine("Page has {0} zones:", ocrPage.Zones.Count)
For i As Integer = 0 To ocrPage.Zones.Count - 1
Dim zone As OcrZone = ocrPage.Zones(i)
Console.WriteLine("{0}: Type: {1}", i + 1, zone.ZoneType)
Next
' Change the OMR options (Auto detection of frames with highest sensitivity)
Dim omrOptions As IOcrOmrOptions = 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
Dim filledCode As Char = omrOptions.GetStateRecognitionCharacter(OcrOmrZoneState.Filled)
Dim unfilledCode As Char = omrOptions.GetStateRecognitionCharacter(OcrOmrZoneState.Unfilled)
' Recognize the page
Console.WriteLine("Recognizing...")
ocrPage.Recognize(Nothing)
Dim pageCharacters As IOcrPageCharacters = ocrPage.GetRecognizedCharacters()
For Each zoneCharacters As IOcrZoneCharacters In pageCharacters
' We must have one character (the state for each OMR zone)
Debug.Assert(zoneCharacters.Count = 1)
Dim character As OcrCharacter = zoneCharacters(0)
Debug.Assert(character.Code = filledCode OrElse character.Code = unfilledCode)
Console.WriteLine("{0}: State: {1}, Confidence: {2}",
zoneCharacters.ZoneIndex,
If(character.Code = filledCode, "Filled", "Unfilled"),
character.Confidence)
Next
' Now save the result as PDF using the default characters representation for OMR states (0 for unfilled, 1 for filled)
Dim pdfFileName1 As String = Path.Combine(LEAD_VARS.ImagesDir, "Omr_Results1.pdf")
Console.WriteLine("Saving to {0}...", pdfFileName1)
ocrDocument.Save(pdfFileName1, DocumentFormat.Pdf, Nothing)
' Change the character representation for the OMR states to Y for unfilled, and X for filled
omrOptions.SetStateRecognitionCharacter(OcrOmrZoneState.Unfilled, "Y"c)
omrOptions.SetStateRecognitionCharacter(OcrOmrZoneState.Filled, "X"c)
Dim pdfFileName2 As String = Path.Combine(LEAD_VARS.ImagesDir, "Omr_Results2.pdf")
Console.WriteLine("Saving to {0}...", pdfFileName2)
ocrDocument.Save(pdfFileName2, DocumentFormat.Pdf, Nothing)
End Using
' Shutdown the engine
' Note: calling Dispose will also automatically shutdown the engine if it has been started
ocrEngine.Shutdown()
End Using
End Sub
Public NotInheritable Class LEAD_VARS
Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
Public Const OcrLEADRuntimeDir As String = "C:\LEADTOOLS 20\Bin\Common\OcrLEADRuntime"
End Class
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