Important Update
The documentation is crafted to assist you to apply the features on your side easily. ByteScout Data Extraction Suite helps with OCR (optical character recognition) in PDF with PDF extractor SDK in ASP.NET C#. ByteScout Data Extraction Suite is the set that includes 3 SDK products for data extraction from PDF, scans, images and from spreadsheets: PDF Extractor SDK, Data Extraction SDK, Barcode Reader SDK.
The below SDK samples describe how to quickly make your application do OCR (optical character recognition) in PDF with PDF extractor SDK in ASP.NET C# with the help of ByteScout Data Extraction Suite. If you want to know how it works, then this ASP.NET C# sample code should be copied and pasted into your application’s code editor. Then just compile and run it. This basic programming language sample code for ASP.NET C# will do the whole work for you in implementing OCR (optical character recognition) in PDF with PDF extractor SDK in your app.
If you want to try other samples for ASP.NET C# then free trial version of ByteScout Data Extraction Suite is available on our website.
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<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="OpticalCharacterRecognition._Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
</div>
</form>
</body>
</html>
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using System;
using Bytescout.PDFExtractor;
// Before running the example, copy missing *.traineddata files from "Redistributable" folder to "ocrdata" project folder.
// or download from https://github.com/bytescout/ocrdata
// Make sure "Copy to Output Directory" property of each added language file is set to "Copy always".
namespace OpticalCharacterRecognition
{
/*
IF YOU SEE TEMPORARY FOLDER ACCESS ERRORS:
Temporary folder access is required for web application when you use ByteScout SDK in it.
If you are getting errors related to the access to temporary folder like "Access to the path 'C:\Windows\TEMP\... is denied" then you need to add permission for this temporary folder to make ByteScout SDK working on that machine and IIS configuration because ByteScout SDK requires access to temp folder to cache some of its data for more efficient work.
SOLUTION:
If your IIS Application Pool has "Load User Profile" option enabled the IIS provides access to user's temp folder. Check user's temporary folder
If you are running Web Application under an impersonated account or IIS_IUSRS group, IIS may redirect all requests into separate temp folder like "c:\temp\".
In this case
- check the User or User Group your web application is running under
- then add permissions for this User or User Group to read and write into that temp folder (c:\temp or c:\windows\temp\ folder)
- restart your web application and try again
*/
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
String inputFile = Server.MapPath(@".\bin\sample_ocr.pdf");
// Location of language files
String ocrLanguageDataFolder = Server.MapPath(@".\bin\ocrdata");
// Create Bytescout.PDFExtractor.TextExtractor instance
using (TextExtractor extractor = new TextExtractor())
{
extractor.RegistrationName = "demo";
extractor.RegistrationKey = "demo";
// Enable Optical Character Recognition (OCR)
// in .Auto mode (SDK automatically checks if needs to use OCR or not)
extractor.OCRMode = OCRMode.Auto;
// Set the location of OCR language data files
extractor.OCRLanguageDataFolder = ocrLanguageDataFolder;
// Set OCR language
extractor.OCRLanguage = "eng"; // "eng" for english, "deu" for German, "fra" for French, "spa" for Spanish etc - according to files in "ocrdata" folder
// Set PDF document rendering resolution
extractor.OCRResolution = 300;
// You can also apply various preprocessing filters
// to improve the recognition on low-quality scans.
// Automatically deskew skewed scans
//extractor.OCRImagePreprocessingFilters.AddDeskew();
// Remove vertical or horizontal lines (sometimes helps to avoid OCR engine's page segmentation errors)
//extractor.OCRImagePreprocessingFilters.AddVerticalLinesRemover();
//extractor.OCRImagePreprocessingFilters.AddHorizontalLinesRemover();
// Repair broken letters
//extractor.OCRImagePreprocessingFilters.AddDilate();
// Remove noise
//extractor.OCRImagePreprocessingFilters.AddMedian();
// Apply Gamma Correction
//extractor.OCRImagePreprocessingFilters.AddGammaCorrection();
// Add Contrast
//extractor.OCRImagePreprocessingFilters.AddContrast(20);
// (!) You can use new OCRAnalyser class to find an optimal set of image preprocessing
// filters for your specific document.
// See "OCR Analyser" example.
// Load PDF document
extractor.LoadDocumentFromFile(inputFile);
// Write extracted text to output stream
Response.Clear();
Response.ContentType = "text/html";
Response.Write("<pre>");
// Write extracted text to output stream
Response.Write(extractor.GetText());
Response.Write("</pre>");
Response.End();
}
}
}
}
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//------------------------------------------------------------------------------
// <auto-generated>
// This code was generated by a tool.
// Runtime Version:2.0.50727.4952
//
// Changes to this file may cause incorrect behavior and will be lost if
// the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------
namespace ExtractAllText {
/// <summary>
/// _Default class.
/// </summary>
/// <remarks>
/// Auto-generated class.
/// </remarks>
public partial class _Default {
/// <summary>
/// form1 control.
/// </summary>
/// <remarks>
/// Auto-generated field.
/// To modify move field declaration from designer file to code-behind file.
/// </remarks>
protected global::System.Web.UI.HtmlControls.HtmlForm form1;
}
}
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<?xml version="1.0"?>
<configuration>
<appSettings/>
<connectionStrings/>
<system.web>
<!--
Set compilation debug="true" to insert debugging
symbols into the compiled page. Because this
affects performance, set this value to true only
during development.
-->
<compilation debug="true" />
<!--
The <authentication> section enables configuration
of the security authentication mode used by
ASP.NET to identify an incoming user.
-->
<authentication mode="Windows" />
<!--
The <customErrors> section enables configuration
of what to do if/when an unhandled error occurs
during the execution of a request. Specifically,
it enables developers to configure html error pages
to be displayed in place of a error stack trace.
<customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
<error statusCode="403" redirect="NoAccess.htm" />
<error statusCode="404" redirect="FileNotFound.htm" />
</customErrors>
-->
</system.web>
</configuration>
60 Day Free Trial or Visit ByteScout Data Extraction Suite Home Page
Explore ByteScout Data Extraction Suite Documentation
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60 Day Free Trial or Visit ByteScout Data Extraction Suite Home Page
Explore ByteScout Data Extraction Suite Documentation
Explore Samples
Sign Up for ByteScout Data Extraction Suite Online Training
Get Your API Key
Explore Web API Docs
Explore Web API Samples
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