SetRecognizedCharacters Method

Summary

Sets the recognized character data of this IOcrPage

Syntax

Objective-C

C++/CLI

Java

Python

public void SetRecognizedCharacters( 
   IOcrPageCharacters pageCharacters 
)

- (BOOL)setRecognizedCharacters:(LTOcrPageCharacters *)pageCharacters error:(NSError **)error

public void setRecognizedCharacters(OcrPageCharacters pageCharacters)

void SetRecognizedCharacters(  
   IOcrPageCharacters^ pageCharacters 
)

def SetRecognizedCharacters(self,pageCharacters):

Parameters

pageCharacters
The modified page characters to set.

Remarks

Use this method to set the recognized characters of a page after you modify them. To get the recognized characters of a page use GetRecognizedCharacters.

You must call this method after the IOcrPage has been recognized with the Recognize method. i.e., if the value of the IsRecognized property of this page is false, then calling this method will throw an exception.

You can use the GetRecognizedCharacters to examine the recognized character data. This data contain information about the character codes, their confidence, guess codes, location and position in the page as well as font information. For more information, refer to OcrCharacter.

The GetRecognizedCharacters method returns an instance of IOcrPageCharacters, this instance is a collection of IOcrZoneCharacters objects. Each of the IOcrZoneCharacters objects will contain the collection of the OcrCharacter that forms a zone in the page. The IOcrZoneCharacters.ZoneIndex property contains the zero-based index of the zone. You can get the zone information by using the same index with the getter of the Zones property of this IOcrPage.

Use IOcrZoneCharacters.GetWords to get the recognized words of a zone.

Notes on spaces: The LEADTOOLS OCR Module - LEAD Engine will not return any space characters when using the GetRecognizedCharacters method.

The SetRecognizedCharacters method will accept space characters in the LEADTOOLS LEAD engine. However, these space characters will be used when generating the final document (PDF) and might affect the final output. Therefore, it is not recommended that you insert space characters when using the LEADTOOLS LEAD engine.

If you use the GetRecognizedCharacters and SetRecognizedCharacters methods to modify the recognition result prior to saving to an output file, and you are planning on using the engine native save capability (through setting the IOcrDocumentManager.EngineFormat property and using DocumentFormat.User in the IOcrDocument.Save method), then you must change the boolean Recognition.SpaceIsValidCharacter setting to true.

The IOcrPageCharacters interface also contains the IOcrPageCharacters.UpdateWord method that allow to modify the OCR recognition results by updating or deleting the words before optionally saving the results to the final output document.

Example

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Ocr; 
using Leadtools.Forms.Common; 
using Leadtools.Document.Writer; 
using Leadtools.WinForms; 
using Leadtools.Drawing; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
 
public void RecognizedCharactersExample() 
{ 
   // Create an image with some text in it 
   RasterImage image = new RasterImage(RasterMemoryFlags.Conventional, 640, 200, 24, RasterByteOrder.Bgr, RasterViewPerspective.TopLeft, null, IntPtr.Zero, 0); 
   Rectangle imageRect = new Rectangle(0, 0, image.ImageWidth, image.ImageHeight); 
 
   IntPtr hdc = RasterImagePainter.CreateLeadDC(image); 
   using (Graphics g = Graphics.FromHdc(hdc)) 
   { 
      g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; 
      g.FillRectangle(Brushes.White, imageRect); 
 
      using (Font f = new Font("Arial", 20, FontStyle.Regular)) 
         g.DrawString("Normal line", f, Brushes.Black, 0, 0); 
 
      using (Font f = new Font("Arial", 20, FontStyle.Bold)) 
         g.DrawString("Bold, italic and underline", f, Brushes.Black, 0, 40); 
 
      using (Font f = new Font("Courier New", 20, FontStyle.Regular)) 
         g.DrawString("Monospaced line", f, Brushes.Black, 0, 80); 
   } 
 
   RasterImagePainter.DeleteLeadDC(hdc); 
 
   string textFileName = Path.Combine(LEAD_VARS.ImagesDir, "MyImageWithTest.txt"); 
   string pdfFileName = Path.Combine(LEAD_VARS.ImagesDir, "MyImageWithTest.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 page 
      IOcrPage ocrPage = ocrEngine.CreatePage(image, OcrImageSharingMode.AutoDispose); 
 
      // Recognize this page 
      ocrPage.Recognize(null); 
 
      // Dump the characters into a text file 
      using (StreamWriter writer = File.CreateText(textFileName)) 
      { 
         IOcrPageCharacters ocrPageCharacters = ocrPage.GetRecognizedCharacters(); 
         foreach (IOcrZoneCharacters ocrZoneCharacters in ocrPageCharacters) 
         { 
            // Show the words found in this zone. Get the word boundaries in inches 
            ICollection<OcrWord> words = ocrZoneCharacters.GetWords(); 
            Console.WriteLine("Words:"); 
            foreach (OcrWord word in words) 
               Console.WriteLine("Word: {0}, at {1}, characters index from {2} to {3}", word.Value, word.Bounds, word.FirstCharacterIndex, word.LastCharacterIndex); 
 
            bool nextCharacterIsNewWord = true; 
 
            for (int i = 0; i < ocrZoneCharacters.Count; i++) 
            { 
               OcrCharacter ocrCharacter = ocrZoneCharacters[i]; 
 
               // Capitalize the first letter if this is a new word 
               if (nextCharacterIsNewWord) 
                  ocrCharacter.Code = Char.ToUpper(ocrCharacter.Code); 
 
               writer.WriteLine("Code: {0}, Confidence: {1}, WordIsCertain: {2}, Bounds: {3}, Position: {4}, FontSize: {5}, FontStyle: {6}", 
                  ocrCharacter.Code, 
                  ocrCharacter.Confidence, 
                  ocrCharacter.WordIsCertain, 
                  ocrCharacter.Bounds, 
                  ocrCharacter.Position, 
                  ocrCharacter.FontSize, 
                  ocrCharacter.FontStyle); 
 
               // If the character is bold, make it underline 
               if ((ocrCharacter.FontStyle & OcrCharacterFontStyle.Bold) == OcrCharacterFontStyle.Bold) 
               { 
                  ocrCharacter.FontStyle |= OcrCharacterFontStyle.Italic; 
                  ocrCharacter.FontStyle |= OcrCharacterFontStyle.Underline; 
               } 
 
               // Check if next character is the start of a new word 
               if ((ocrCharacter.Position & OcrCharacterPosition.EndOfWord) == OcrCharacterPosition.EndOfWord || 
                  (ocrCharacter.Position & OcrCharacterPosition.EndOfLine) == OcrCharacterPosition.EndOfLine) 
                  nextCharacterIsNewWord = true; 
               else 
                  nextCharacterIsNewWord = false; 
 
               ocrZoneCharacters[i] = ocrCharacter; 
            } 
         } 
 
         // Replace the characters with the modified one before we save 
         ocrPage.SetRecognizedCharacters(ocrPageCharacters); 
      } 
 
      // Create an OCR document so we can save the results 
      using (IOcrDocument ocrDocument = ocrEngine.DocumentManager.CreateDocument(null, OcrCreateDocumentOptions.AutoDeleteFile)) 
      { 
         // Add the page and dispose it 
         ocrDocument.Pages.Add(ocrPage); 
         ocrPage.Dispose(); 
 
         // Show the recognition results 
         // Set the PDF options to save as PDF/A text only 
         PdfDocumentOptions pdfOptions = ocrEngine.DocumentWriterInstance.GetOptions(DocumentFormat.Pdf) as PdfDocumentOptions; 
         pdfOptions.DocumentType = PdfDocumentType.PdfA; 
         pdfOptions.ImageOverText = false; 
         ocrEngine.DocumentWriterInstance.SetOptions(DocumentFormat.Pdf, pdfOptions); 
 
         ocrDocument.Save(pdfFileName, DocumentFormat.Pdf, null); 
 
         // Open and check the result file, it should contain the following text 
         // "Normal Line" 
         // "Bold And Italic Line" 
         // "Monospaced Line" 
         // With the second line bold and underlined now 
      } 
 
      // 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"; 
}