Before using OCR features, you should setup OCR modules first. For more information, see OCR Module Installation.

Perform OCR on a Document

The following code performs OCR on a document at once using Document.PerformOCR Method. This is the easiest way to perform OCR.

djvuocr.cs	Copy Code
using System; using DjVu; namespace DjVuOcr { class DjVuOcr { static void Main(string[] args) { // TODO: ADD app's license script here or REMOVE the following line LicenseManager.LicenseScript = "......"; using (Document doc = new Document(args[0])) { doc.PerformOCR(false); doc.SaveAs(args[1]); } } } }

djvuocr.cs

Copy Code

using System;
using DjVu;
namespace DjVuOcr
{
  class DjVuOcr
  {
    static void Main(string[] args)
    {
      // TODO: ADD app's license script here or REMOVE the following line
      LicenseManager.LicenseScript = "......"; 

      using (Document doc = new Document(args[0]))
      {
        doc.PerformOCR(false);
        doc.SaveAs(args[1]);
      }
    }
  }
}

Perform OCR Page by Page

Of course, you can perform OCR on page by page basis. This is better if you want to interact with user because you can add some GUI/CUI codes around the OCR call.

djvuocrpxp.cs	Copy Code
using System; using DjVu; namespace SavePageByPage { class SavePageByPage { static void Main(string[] args) { // TODO: ADD app's license script here or REMOVE the following line LicenseManager.LicenseScript = "......"; using (Document doc = new Document(args[0])) { for (int i = 0; i < doc.Pages.Count; i++) { Console.WriteLine("OCR {0}/{1}...", i + 1, doc.Pages.Count); doc.Pages[i].PerformOCR(false); } doc.SaveAs(args[1]); } } } }

djvuocrpxp.cs

Copy Code

using System;
using DjVu;
namespace SavePageByPage
{
  class SavePageByPage
  {
    static void Main(string[] args)
    {
      // TODO: ADD app's license script here or REMOVE the following line
      LicenseManager.LicenseScript = "......"; 

      using (Document doc = new Document(args[0]))
      {
        for (int i = 0; i < doc.Pages.Count; i++)
        {
          Console.WriteLine("OCR {0}/{1}...", i + 1, doc.Pages.Count);
          doc.Pages[i].PerformOCR(false);
        }
        doc.SaveAs(args[1]);
      }
    }
  }
}

Configuring OCR Parameters

Basically, OCR parameters are initialized automatically based on the thread locale. On typical situation, if the machine is running Japanese Windows XP, the OCR is configured for Japanese by default. You can override the default settings by explicitly passing OcrSettings Class object to OCR methods.

Some PerformOCR methods do not accept OcrSettings object and they use the global settings. The global OCR parameters can be configured using GlobalOcrSettings Class.

djvuocrja.cs	Copy Code
using System; using DjVu; namespace DjVuOcr { class DjVuOcr { static void Main(string[] args) { // TODO: ADD app's license script here or REMOVE the following line LicenseManager.LicenseScript = "......"; using (Document doc = new Document(args[0])) { // Explicitly configure OCR for Japanese Ocr.OcrSettings os = new Ocr.OcrSettings(Ocr.Language.Japanese); doc.PerformOCR(os, false); doc.SaveAs(args[1]); } } } }

djvuocrja.cs

Copy Code

using System;
using DjVu;
namespace DjVuOcr
{
  class DjVuOcr
  {
    static void Main(string[] args)
    {
      // TODO: ADD app's license script here or REMOVE the following line
      LicenseManager.LicenseScript = "......"; 

      using (Document doc = new Document(args[0]))
      {
        // Explicitly configure OCR for Japanese
        Ocr.OcrSettings os = new Ocr.OcrSettings(Ocr.Language.Japanese);

        doc.PerformOCR(os, false);
        doc.SaveAs(args[1]);
      }
    }
  }
}