Recognize(int,int,OcrProgressCallback) Method

Summary

Recognizes the OCR data found on a range of pages in the OCR document.

Syntax

Objective-C

C++/CLI

Java

Python

public void Recognize( 
   int firstPageIndex, 
   int lastPageIndex, 
   OcrProgressCallback callback 
)

- (BOOL)recognizePagesInRange:(NSRange)range 
                     progress:(nullable LTOcrProgressHandler)progressHandler 
                        error:(NSError **)error

public void recognize(int firstPageIndex, 
                      int lastPageIndex, 
                      OcrProgressListener callback)

void Recognize(  
   int firstPageIndex, 
   int lastPageIndex, 
   OcrProgressCallback^ callback 
)

def Recognize(self,firstPageIndex,lastPageIndex,callback):

Parameters

firstPageIndex
The zero-based index of the first page to recognize.

lastPageIndex
The zero-based index of the last page to recognize. A value of -1 means recognize up to and including the last page in the OCR document.

callback
Optional callback to show operation progress.

Remarks

For more information on recognition of OCR data a page, refer to IOcrPage.Recognize.

This method will iterate through all the pages between firstPageIndex and lastPageIndex in the OCR document and run IOcrPage.Recognize on each page.

To recognize all the pages in the OCR document use Recognize(OcrProgressCallback callback).

You can use the OcrProgressCallback to show the operation progress or to abort it. For more information and an example, refer to OcrProgressCallback.

This member only works with memory-based documents and will throw an exception otherwise. For more information, refer to IOcrDocumentManager.CreateDocument and Programming with the LEADTOOLS .NET OCR.

Example

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Ocr; 
using Leadtools.Document.Writer; 
using Leadtools.Forms.Common; 
using Leadtools.ImageProcessing.Core; 
 
public void PageCollectionExamples() 
{ 
   // For this example, we need a multi-page TIF file. 
   // Create a muti-page TIF from Ocr1.tif, Ocr2.tif, Ocr3.tif and Ocr4.tif 
   string tifFileName = Path.Combine(LEAD_VARS.ImagesDir, "Ocr.tif"); 
   if (File.Exists(tifFileName)) 
      File.Delete(tifFileName); 
 
   using (RasterCodecs codecs = new RasterCodecs()) 
   { 
      for (int i = 0; i < 4; i++) 
      { 
         string pageFileName = Path.Combine(LEAD_VARS.ImagesDir, string.Format("Ocr{0}.tif", i + 1)); 
         using (RasterImage image = codecs.Load(pageFileName)) 
            codecs.Save(image, tifFileName, RasterImageFormat.CcittGroup4, 1, 1, 1, -1, CodecsSavePageMode.Append); 
      } 
   } 
 
   string pdfFileName = Path.Combine(LEAD_VARS.ImagesDir, "Ocr.pdf"); 
 
   // 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); 
 
      // Create an OCR document 
      using (IOcrDocument ocrDocument = ocrEngine.DocumentManager.CreateDocument()) 
      { 
         // Load all the pages of the multi-page tif file we created into the form 
         ocrDocument.Pages.AddPages(tifFileName, 1, -1, null); 
         Console.WriteLine("{0} pages added to the document", ocrDocument.Pages.Count); 
 
         // Auto-zone 
         ocrDocument.Pages.AutoZone(null); 
 
         // Recognize 
         ocrDocument.Pages.Recognize(null); 
 
         // Save 
         ocrDocument.Save(pdfFileName, 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:\LEADTOOLS22\Resources\Images"; 
   public const string OcrLEADRuntimeDir = @"C:\LEADTOOLS22\Bin\Common\OcrLEADRuntime"; 
}