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PageRequestCallback Delegate

Summary
Delegate method that is used to request a page and provide the requested page to the caller method.

Syntax
C#
C++/CLI
Java
Python
public delegate void PageRequestCallback( 
   PageRequestCallbackData data 
) 
public interface PageRequestCallback 
public delegate void PageRequestCallback(  
   PageRequestCallbackData^ data 
) 
def PageRequestCallback(self,data): 
# data : PageRequestCallbackData 

Parameters

data
An instance of the PageRequestCallbackData interface containing the requested image information.

Remarks

This delegate is useful when the number of form pages is not known before recognizing the form or when the users does not want to load all image pages in the memory or load them via network while he needs to process few of them. So the user loads the first page of the form and uses it for recognition, then for processing he will be asked to provide only the pages that have processing fields.

Example
C#
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Forms.Common; 
using Leadtools.Forms.Auto; 
using Leadtools.Document; 
using Leadtools.Ocr; 
using Leadtools.Forms.Recognition; 
using Leadtools.Forms.Processing; 
using Leadtools.Barcode; 
 
using Leadtools.Forms; 
 
public RasterCodecs Codecs; 
public string FormFileName; 
 
public void MyPageRequestCallback(PageRequestCallbackData data) 
{ 
   data.Page = Codecs.Load(FormFileName, 1, CodecsLoadByteOrder.Bgr, data.FormPageNumber, data.FormPageNumber); 
} 
public void AutoFormRunAutomatic() 
{ 
   string root = Path.Combine(LEAD_VARS.ImagesDir, @"Forms\FormsDemo\OCR_Test"); 
   RasterCodecs codecs = new RasterCodecs(); 
   //create repository 
   DiskMasterFormsRepository repository = new DiskMasterFormsRepository(codecs, root); 
 
   using (IOcrEngine ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD)) 
   { 
      ocrEngine.Startup(null, null, null, LEAD_VARS.OcrLEADRuntimeDir); 
      BarcodeEngine barcodeEngine = new BarcodeEngine(); 
 
      //create AutoForm Engine 
      AutoFormsEngine autoEngine = new AutoFormsEngine(repository, ocrEngine, barcodeEngine); 
      //set the flag to process the first page only 
      autoEngine.RecognizeFirstPageOnly = true; 
      autoEngine.MinimumConfidenceKnownForm = 40; 
      //calculate the minimum confidence recognized form according to the correlation between the master forms in the repository 
      autoEngine.MinimumConfidenceRecognized = autoEngine.GetMinimumRecognizedConfidenceForm(); 
 
      Codecs = codecs; 
      FormFileName = Path.Combine(LEAD_VARS.ImagesDir, @"Forms\Forms to be Recognized\OCR\FCC-107_OCR_Filled.tif"); 
      //load the first page of the image 
      RasterImage form = codecs.Load(FormFileName, 1, CodecsLoadByteOrder.Bgr, 1, 1); 
      //recognize and process the form 
      AutoFormsRunResult result = autoEngine.Run(form, MyPageRequestCallback, null, null); 
      if (result == null) 
         return; 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
   public const string OcrLEADRuntimeDir = @"C:\LEADTOOLS23\Bin\Common\OcrLEADRuntime"; 
} 
Requirements

Target Platforms

See Also

Reference

PageRequestCallback Members

Leadtools.Forms.Auto Namespace

Help Version 23.0.2024.2.29
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Leadtools.Forms.Auto Assembly
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.