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IOcrDocumentManager Interface

Manages the OCR documents of this IOcrEngine.
public interface IOcrDocumentManager 
@interface LTOcrDocumentManager : NSObject 
public class OcrDocumentManager 
public interface class IOcrDocumentManager  
class IOcrDocumentManager: 

You can access the instance of the IOcrDocumentManager used by an IOcrEngine through the IOcrEngine.DocumentManager property.

The IOcrDocumentManager interface allows you to create IOcrDocument objects that encapsulate an OCR'ed document. Each OCR document contains a collection of IOcrPage that you can use to add and remove pages from the document. After you add the pages to the document and optionally manage the zones on the pages, you can call the IOcrPage.Recognize method on each page to obtain the recognition data and store them internally in the pages. Once you are done, you can use the save methods of the IOcrDocument object to save the document into its final format.

LEADTOOLS supports saving to various standard document formats such as PDF, Microsoft Word, HTML and several others through the LEADTOOLS Document Writers engine. For more information, refer to IOcrDocument and DocumentFormat.

IOcrDocumentManager supports creating documents in two ways:

Memory-Based Documents

In this mode, the OCR pages are required to be in memory before saving. This is not recommended when the document have a large amount of pages and either using a file-based document or using the LEADTOOLS Temporary file format (DocumentFormat.Ltd is required.

In memory-based IOcrDocument, the IOcrPageCollection holds the pages. The user can recognize any or all of the pages at any time and pages can be added or removed at will.

Use or IOcrDocumentManager.CreateDocument or IOcrDocumentManager.CreateDocument(string, OcrCreateDocumentOptions) with the OcrCreateDocumentOptions.InMemory flag to create such documents.

IOcrDocument.IsInMemory will be true for memory-based documents.

File-Based Documents

In this mode, the OCR pages are not required to be in memory before saving. This mode is recommended when the document have a large amount of pages and.

In file-based IOcrDocument, the IOcrPageCollection is a store-only view of the pages. when page is added, a snap shot of the current recognition data is saved into the document. This data cannot be modified any more and the page is no longer needed. The user must recognize the pages before they are added to the document and pages can only be added but not removed.

File-based documents can also be saved and re-loaded to continue adding pages or converting to final document at a later time. For more information and examples, refer to Programming with the LEADTOOLS .NET OCR.

Use IOcrDocumentManager.CreateDocument(string, OcrCreateDocumentOptions) without the OcrCreateDocumentOptions.InMemory flag to create such documents.

IOcrDocument.IsInMemory will be false for memory-based documents. The current back-end file name can be obtained through IOcrDocument.FileName.

Typical OCR operation using the IOcrEngine involves starting up the engine, create an IOcrDocument object using the IOcrDocumentManager.CreateDocument method and adding the pages into it and perform either automatic or manual zoning. Once this is done, After the recognition data is collected using IOcrPage.Recognize, you use the various IOcrDocument.Save methods to save the document to its final format such as PDF, DOC or HTML.

In addition to the above, you can use IOcrDocument.SaveXml to save the document as XML.


This example save a page to all the formats supported by the LEADTOOLS OCR Module - LEAD Engine.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Ocr; 
using Leadtools.Forms.Common; 
using Leadtools.Document.Writer; 
using Leadtools.WinForms; 
public void OcrDocumentManagerExample() 
   string tifFileName1 = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.tif"); 
   string tifFileName2 = Path.Combine(LEAD_VARS.ImagesDir, "Ocr2.tif"); 
   string outputDirectory = Path.Combine(LEAD_VARS.ImagesDir, "OutputDirectory"); 
   // Create the output directory 
   if (Directory.Exists(outputDirectory)) 
      Directory.Delete(outputDirectory, true); 
   // Create an instance of the engine 
   using (IOcrEngine ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD)) 
      // Start the engine using default parameters 
      Console.WriteLine("Starting up the engine..."); 
      ocrEngine.Startup(null, null, null, LEAD_VARS.OcrLEADRuntimeDir); 
      // Create the OCR document 
      Console.WriteLine("Creating the OCR document..."); 
      IOcrDocumentManager ocrDocumentManager = ocrEngine.DocumentManager; 
      using (IOcrDocument ocrDocument = ocrDocumentManager.CreateDocument()) 
         // Add the pages to the document 
         Console.WriteLine("Adding the pages..."); 
         ocrDocument.Pages.AddPage(tifFileName1, null); 
         ocrDocument.Pages.AddPage(tifFileName2, null); 
         // Recognize the pages to this document. Note, we did not call AutoZone, it will explicitly be called by Recognize 
         Console.WriteLine("Recognizing all the pages..."); 
         // Save to all the formats supported by this OCR engine 
         Array formats = Enum.GetValues(typeof(DocumentFormat)); 
         foreach (DocumentFormat format in formats) 
            string friendlyName = DocumentWriter.GetFormatFriendlyName(format); 
            Console.WriteLine("Saving (using default options) to {0}...", friendlyName); 
            // Construct the output file name (output_directory + document_format_name + . + extension) 
            string extension = DocumentWriter.GetFormatFileExtension(format); 
            string outputFileName = Path.Combine(outputDirectory, format.ToString() + "." + extension); 
            // Save the document 
            ocrDocument.Save(outputFileName, format, null); 
            // If this is the LTD format, convert it to PDF 
            if (format == DocumentFormat.Ltd) 
               Console.WriteLine("Converting the LTD file to PDF..."); 
               string pdfFileName = Path.Combine(outputDirectory, format.ToString() + "_pdf.pdf"); 
               DocumentWriter docWriter = ocrEngine.DocumentWriterInstance; 
               docWriter.Convert(outputFileName, pdfFileName, DocumentFormat.Pdf); 
         // Now save to all the engine native formats (if any) supported by the engine 
         string[] engineFormats = ocrDocumentManager.GetSupportedEngineFormats(); 
         foreach (string engineFormat in engineFormats) 
            string friendlyName = ocrDocumentManager.GetEngineFormatFriendlyName(engineFormat); 
            Console.WriteLine("Saving to engine native format {0}...", friendlyName); 
            // Construct the output file name (output_directory + "engine" + engine_format_name + . + extension) 
            string extension = ocrDocumentManager.GetEngineFormatFileExtension(engineFormat); 
            string outputFileName = Path.Combine(outputDirectory, "engine_" + engineFormat + "." + extension); 
            // To use this format, set it in the IOcrDocumentManager.EngineFormat and do a normal save using DocumentFormat.User 
            // Save the document 
            ocrDocumentManager.EngineFormat = engineFormat; 
            ocrDocument.Save(outputFileName, DocumentFormat.User, null); 
      // Shutdown the engine 
      // Note: calling Dispose will also automatically shutdown the engine if it has been started 
      Console.WriteLine("Shutting down..."); 
static class LEAD_VARS 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
   public const string OcrLEADRuntimeDir = @"C:\LEADTOOLS22\Bin\Common\OcrLEADRuntime"; 

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Leadtools.Ocr Assembly

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