AddPages(Stream,int,int,OcrProgressCallback) Method

Summary

Adds one or more pages from a .NET stream containing a multipage image file.

Syntax

Objective-C

C++/CLI

Java

Python

public void AddPages( 
   Stream stream, 
   int imageFirstPageNumber, 
   int imageLastPageNumber, 
   OcrProgressCallback callback 
)

- (BOOL)addPagesWithStream:(LTLeadStream *)stream  
                   inRange:(NSRange)range  
                     error:(NSError **)error

public void addPages(ILeadStream stream, 
                     int imageFirstPageNumber, 
                     int imageLastPageNumber, 
                     OcrProgressListener callback)

void AddPages(  
   Stream^ stream, 
   int imageFirstPageNumber, 
   int imageLastPageNumber, 
   OcrProgressCallback^ callback 
)

def AddPages(self,stream,imageFirstPageNumber,imageLastPageNumber,callback):

Parameters

stream
The .NET stream containing the multipage image file.

imageFirstPageNumber
1-based index of the first page in stream to add.

imageLastPageNumber
1-based index of the last page in stream to add. A value of -1 means add up to and including the last page in stream.

callback
Optional callback to show operation progress.

Remarks

A short-cut to add all the pages in a .NET stream to the OCR document is AddPages(stream, 1, -1, callback).

To add the first page from a multipage file stored in a .NET stream, you can also use AddPage(Stream stream, OcrProgressCallback callback).

This method will add the page(s) to the end of the collection if you already have pages in this IOcrPageCollection.

The image file in stream can be any of the file formats supported by LEADTOOLS. For more information, refer to Summary of All Supported Image File Formats.

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

The LEADTOOLS OCR engine supports pages of dots per inch (DPI) values of 150 and greater. If you try to add a page with a DPI of less than 150 then the engine might be able to recognize any data from this page.

Note: The value of the "Recognition.ShareOriginalImage" (only supported by the LEADTOOLS OCR Module - LEAD Engine) setting is not used when calling this method. The engine loads the image(s) and sets them in the pages internally. The original image reference can be obtained from the page using IOcrPage.GetRasterImage(OcrPageType.Original). Sharing the original image minimizes the memory used during OCR operations.

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

Java

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:\LEADTOOLS23\Resources\Images"; 
   public const string OcrLEADRuntimeDir = @"C:\LEADTOOLS23\Bin\Common\OcrLEADRuntime"; 
}

 
import java.io.File; 
import java.io.IOException; 
import java.net.URI; 
import java.net.URISyntaxException; 
 
import org.junit.*; 
import org.junit.runner.JUnitCore; 
import org.junit.runner.Result; 
import org.junit.runner.notification.Failure; 
import static org.junit.Assert.*; 
 
import leadtools.*; 
import leadtools.codecs.*; 
import leadtools.document.writer.DocumentFormat; 
import leadtools.imageprocessing.core.DeskewCommand; 
import leadtools.imageprocessing.core.DeskewCommandFlags; 
import leadtools.ocr.OcrDocument; 
import leadtools.ocr.OcrEngine; 
import leadtools.ocr.OcrEngineManager; 
import leadtools.ocr.OcrEngineType; 
 
 
public void IOcrPageCollectionsPageCollectionExamples() { 
   final String LEAD_VARS_IMAGES_DIR = "C:\\LEADTOOLS23\\Resources\\Images"; 
   final String LEAD_VARS_OCR_LEAD_RUNTIME_DIR = "C:\\LEADTOOLS23\\Bin\\Common\\OcrLEADRuntime"; 
 
   // 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 
   var tifFileName = combine(LEAD_VARS_IMAGES_DIR, "Ocr.tif"); 
   var file = new File(tifFileName); 
   if (file.exists()) 
      file.delete(); 
 
   RasterCodecs codecs = new RasterCodecs(); 
   for (var i = 0; i < 4; i++) { 
      var pageFileName = combine(LEAD_VARS_IMAGES_DIR, "Ocr" + (i + 1) + ".tif"); 
      var image = codecs.load(pageFileName); 
      codecs.save(image, tifFileName, RasterImageFormat.CCITT_GROUP4, 1, 1, 1, -1, CodecsSavePageMode.APPEND); 
   } 
   codecs = null; 
 
   var pdfFileName = combine(LEAD_VARS_IMAGES_DIR, "Ocr.pdf"); 
 
   codecs = new RasterCodecs(); 
   // Create an instance of the engine 
   OcrEngine ocrEngine = OcrEngineManager.createEngine(OcrEngineType.LEAD); 
 
   // Start the engine using default parameters 
   ocrEngine.startup(codecs, null, null, LEAD_VARS_OCR_LEAD_RUNTIME_DIR); 
   assertTrue("Engine unsuccessfully started", ocrEngine.isStarted()); 
 
   // Create an OCR document 
   OcrDocument ocrDocument = ocrEngine.getDocumentManager().createDocument(); 
 
   // Load all the pages of the multi-page tif file we created into the form 
   ocrDocument.getPages().addPages(codecs.load(tifFileName), 1, -1, null); 
   System.out.println(ocrDocument.getPages().size() + " pages added to the document"); 
 
   // Auto-zone 
   ocrDocument.getPages().autoZone(null); 
 
   // Recognize 
   ocrDocument.getPages().recognize(null); 
 
   // Save 
   ocrDocument.save(pdfFileName, DocumentFormat.PDF, null); 
   assertTrue("File unsuccessfully saved", (new File(tifFileName)).exists()); 
 
   // Shutdown the engine 
   // Note: calling Dispose will also automatically shutdown the engine if it has 
   // been started 
   ocrEngine.shutdown(); 
}