How to implement and do OCR in a C# project?

I ve been searching for a while and all that i ve seen some OCR library requests. I would like to know how to implement the purest, easy to install and use OCR library with detailed info for installation into a C# project.

If posible, I just wanna implement it like a usual dll reference...

Example:

using org.pdfbox.pdmodel;
using org.pdfbox.util;


Also a little OCR code example would be nice, such as:

public string OCRFromBitmap(Bitmap Bmp)

Bmp.Save(temppath, System.Drawing.Imaging.ImageFormat.Tiff);
string OcrResult = Analyze(temppath);
File.Delete(temppath);
return OcrResult;



So please consider that I'm not familiar to OCR projects and give me an answer like talking to a dummy.

Edit:
I guess people misunderstood my request. I wanted to know how to implement those open source OCR libraries to a C# project and how to use them. The link given as dup is not giving answers that I requested at all.

5 Answers
5

Here's one: (check out http://hongouru.blogspot.ie/2011/09/c-ocr-optical-character-recognition.html or http://www.codeproject.com/Articles/41709/How-To-Use-Office-2007-OCR-Using-C for more info)

using MODI;
static void Main(string args)

DocumentClass myDoc = new DocumentClass();
myDoc.Create(@"theDocumentName.tiff"); //we work with the .tiff extension
myDoc.OCR(MiLANGUAGES.miLANG_ENGLISH, true, true);

foreach (Image anImage in myDoc.Images)

Console.WriteLine(anImage.Layout.Text); //here we cout to the console.




If anyone is looking into this, I've been trying different options and the following approach yields very good results. The following are the steps to get a working example:

Install-Package Tesseract

tesseract-ocr-3.02.eng.tar.gz English language data for Tesseract 3.02

tessdata

Properties

System.Drawing

Samples

phototest.tif

Program.cs

using System;
using Tesseract;
using System.Diagnostics;

namespace ConsoleApplication

class Program

public static void Main(string args)

var testImagePath = "./phototest.tif";
if (args.Length > 0)

testImagePath = args[0];


try

var logger = new FormattedConsoleLogger();
var resultPrinter = new ResultPrinter(logger);
using (var engine = new TesseractEngine(@"./tessdata", "eng", EngineMode.Default))

using (var img = Pix.LoadFromFile(testImagePath))

using (logger.Begin("Process image"))

var i = 1;
using (var page = engine.Process(img))

var text = page.GetText();
logger.Log("Text: 0", text);
logger.Log("Mean confidence: 0", page.GetMeanConfidence());

using (var iter = page.GetIterator())

iter.Begin();
do

if (i % 2 == 0)

using (logger.Begin("Line 0", i))

do

using (logger.Begin("Word Iteration"))

if (iter.IsAtBeginningOf(PageIteratorLevel.Block))

logger.Log("New block");

if (iter.IsAtBeginningOf(PageIteratorLevel.Para))

logger.Log("New paragraph");

if (iter.IsAtBeginningOf(PageIteratorLevel.TextLine))

logger.Log("New line");

logger.Log("word: " + iter.GetText(PageIteratorLevel.Word));

while (iter.Next(PageIteratorLevel.TextLine, PageIteratorLevel.Word));


i++;
while (iter.Next(PageIteratorLevel.Para, PageIteratorLevel.TextLine));






catch (Exception e)

Trace.TraceError(e.ToString());
Console.WriteLine("Unexpected Error: " + e.Message);
Console.WriteLine("Details: ");
Console.WriteLine(e.ToString());

Console.Write("Press any key to continue . . . ");
Console.ReadKey(true);




private class ResultPrinter

readonly FormattedConsoleLogger logger;

public ResultPrinter(FormattedConsoleLogger logger)

this.logger = logger;


public void Print(ResultIterator iter)

logger.Log("Is beginning of block: 0", iter.IsAtBeginningOf(PageIteratorLevel.Block));
logger.Log("Is beginning of para: 0", iter.IsAtBeginningOf(PageIteratorLevel.Para));
logger.Log("Is beginning of text line: 0", iter.IsAtBeginningOf(PageIteratorLevel.TextLine));
logger.Log("Is beginning of word: 0", iter.IsAtBeginningOf(PageIteratorLevel.Word));
logger.Log("Is beginning of symbol: 0", iter.IsAtBeginningOf(PageIteratorLevel.Symbol));

logger.Log("Block text: "0"", iter.GetText(PageIteratorLevel.Block));
logger.Log("Para text: "0"", iter.GetText(PageIteratorLevel.Para));
logger.Log("TextLine text: "0"", iter.GetText(PageIteratorLevel.TextLine));
logger.Log("Word text: "0"", iter.GetText(PageIteratorLevel.Word));
logger.Log("Symbol text: "0"", iter.GetText(PageIteratorLevel.Symbol));






FormattedConsoleLogger.cs

using System;
using System.Collections.Generic;
using System.Text;
using Tesseract;

namespace ConsoleApplication

public class FormattedConsoleLogger

const string Tab = " ";
private class Scope : DisposableBase

private int indentLevel;
private string indent;
private FormattedConsoleLogger container;

public Scope(FormattedConsoleLogger container, int indentLevel)

this.container = container;
this.indentLevel = indentLevel;
StringBuilder indent = new StringBuilder();
for (int i = 0; i < indentLevel; i++)

indent.Append(Tab);

this.indent = indent.ToString();


public void Log(string format, object args)

var message = String.Format(format, args);
StringBuilder indentedMessage = new StringBuilder(message.Length + indent.Length * 10);
int i = 0;
bool isNewLine = true;
while (i < message.Length)


Console.WriteLine(indentedMessage.ToString());



public Scope Begin()

return new Scope(container, indentLevel + 1);


protected override void Dispose(bool disposing)

if (disposing)

var scope = container.scopes.Pop();
if (scope != this)

throw new InvalidOperationException("Format scope removed out of order.");





private Stack<Scope> scopes = new Stack<Scope>();

public IDisposable Begin(string title = "", params object args)

Log(title, args);
Scope scope;
if (scopes.Count == 0)

scope = new Scope(this, 1);

else

scope = ActiveScope.Begin();

scopes.Push(scope);
return scope;


public void Log(string format, params object args)

if (scopes.Count > 0)

ActiveScope.Log(format, args);

else

Console.WriteLine(String.Format(format, args));



private Scope ActiveScope

get

var top = scopes.Peek();
if (top == null) throw new InvalidOperationException("No current scope");
return top;






I'm using tesseract OCR engine with TessNet2 (a C# wrapper - http://www.pixel-technology.com/freeware/tessnet2/).

Some basic code:

using tessnet2;


...

Bitmap image = new Bitmap(@"u:user filesbwalker2849257.tif");
tessnet2.Tesseract ocr = new tessnet2.Tesseract();
ocr.SetVariable("tessedit_char_whitelist", "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz.,$-/#&=()"':?"); // Accepted characters
ocr.Init(@"C:UsersbwalkerDocumentsVisual Studio 2010ProjectstessnetWinFormstessnetWinFormsbinRelease", "eng", false); // Directory of your tessdata folder
List<tessnet2.Word> result = ocr.DoOCR(image, System.Drawing.Rectangle.Empty);
string Results = "";
foreach (tessnet2.Word word in result)

Results += word.Confidence + ", " + word.Text + ", " + word.Left + ", " + word.Top + ", " + word.Bottom + ", " + word.Right + "n";



There is a .NET wrapper for Tesseract 3.01: https://github.com/charlesw/tesseract-ocr-dotnet

Another Option to this is to use Neevia Document Converter which has inbuilt OCR capability. You can run pretty much any file type and it will product a pdf that is essential a big text document, which you can then open and search through using ITextSharper

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