Configurations & Languages

Fine-tune the OCR engine for perfect results. Get granular control over performance and accuracy, with out-of-the-box support for 125+ languages.

OCR Detailed Configurations

Normal OCR Configurations

Fine-tune the core Tesseract engine with granular control over dozens of parameters. This offers deep customization for advanced users looking to optimize performance for specific document types, languages, or quality challenges.

Learn how to:C# Tesseract OCR Configuration Variables

IronTesseract ocr = new IronTesseract
{
    Configuration = new TesseractConfiguration
    {
        ReadBarCodes = false,
        RenderHocr = true,
        TesseractVariables = null,
        WhiteListCharacters = null,
        BlackListCharacters = "`ë|^",
    },
    MultiThreaded = false,
    Language = OcrLanguage.English,
    EnableTesseractConsoleMessages = true, // False as default
};

IronTesseract ocr = new IronTesseract
{
    Configuration = new TesseractConfiguration
    {
        ReadBarCodes = false,
        RenderHocr = true,
        TesseractVariables = null,
        WhiteListCharacters = null,
        BlackListCharacters = "`ë|^",
    },
    MultiThreaded = false,
    Language = OcrLanguage.English,
    EnableTesseractConsoleMessages = true, // False as default
};

Dim ocr As New IronTesseract With {
    .Configuration = New TesseractConfiguration With {
        .ReadBarCodes = False,
        .RenderHocr = True,
        .TesseractVariables = Nothing,
        .WhiteListCharacters = Nothing,
        .BlackListCharacters = "`ë|^"
    },
    .MultiThreaded = False,
    .Language = OcrLanguage.English,
    .EnableTesseractConsoleMessages = True
}

OCR Configurations for Advanced Reading

Learn more about OCR configuration settings and languages available for Advanced OCR reading methods.

using IronOcr;

IronTesseract ocr = new IronTesseract
{
    Configuration = new TesseractConfiguration
    {
        // Whitelist alphanumeric characters and common punctuation
        WhiteListCharacters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789.,-?!$() /",
        // Blacklist uncommon characters 
        BlackListCharacters = "`ë|^",
    },

    // Languages available for advanced reading are English, Japanese, Korean, LatinAlphabet   
    Language = OcrLanguage.English
};

using IronOcr;

IronTesseract ocr = new IronTesseract
{
    Configuration = new TesseractConfiguration
    {
        // Whitelist alphanumeric characters and common punctuation
        WhiteListCharacters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789.,-?!$() /",
        // Blacklist uncommon characters 
        BlackListCharacters = "`ë|^",
    },

    // Languages available for advanced reading are English, Japanese, Korean, LatinAlphabet   
    Language = OcrLanguage.English
};

Imports IronOcr

Dim ocr As New IronTesseract With {
    .Configuration = New TesseractConfiguration With {
        .WhiteListCharacters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789.,-?!$() /",
        .BlackListCharacters = "`ë|^"
    },
    .Language = OcrLanguage.English
}

Fast OCR Configuration

Optimize the OCR engine for maximum speed. By adjusting settings to prioritize performance over absolute accuracy, you can rapidly process huge volumes of documents where speed is the critical factor.

Learn how to:Faster Tesseract OCR for .NET

Languages

125 Languages OCR supported

Achieve high accuracy in 125+ international languages. Our packs include robust support for non-Latin scripts (e.g., Arabic, Chinese, Hebrew) and languages with diacritics. Easily add or switch languages with a single line of code.

Learn how to:Master Multi-Language OCR with Iron OCR: English & Japanese

using IronOcr;

var ocr = new IronTesseract();

// Set the OCR to use Chinese Simplified
ocr.Language = OcrLanguage.ChineseSimplified;
using (var input = new OcrInput())
{
    var result = ocr.Read(input);

    // Store the recognized text in a string
    string testResult = result.Text;
}

using IronOcr;

var ocr = new IronTesseract();

// Set the OCR to use Chinese Simplified
ocr.Language = OcrLanguage.ChineseSimplified;
using (var input = new OcrInput())
{
    var result = ocr.Read(input);

    // Store the recognized text in a string
    string testResult = result.Text;
}

Imports IronOcr

Dim ocr As New IronTesseract()

' Set the OCR to use Chinese Simplified
ocr.Language = OcrLanguage.ChineseSimplified
Using input As New OcrInput()
    Dim result = ocr.Read(input)

    ' Store the recognized text in a string
    Dim testResult As String = result.Text
End Using

Multi-Language Reading

Accurately extract text from documents containing multiple languages on the same page. IronOcr automatically detects and switches between specified languages, eliminating the need for separate processing for each language content.

Learn how to:Use Multiple Languages with Tesseract

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract()
{   // Set primary language to English
    Language = OcrLanguage.EnglishBest,
};

// Set secondary language to Russian
ocrTesseract.AddSecondaryLanguage(OcrLanguage.Russian);

// Add PDF
using var pdfInput = new OcrPdfInput(@"example.pdf");

// Perform OCR
OcrResult result = ocrTesseract.Read(pdfInput);

// Output extracted text to console
Console.WriteLine(result.Text);

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract()
{   // Set primary language to English
    Language = OcrLanguage.EnglishBest,
};

// Set secondary language to Russian
ocrTesseract.AddSecondaryLanguage(OcrLanguage.Russian);

// Add PDF
using var pdfInput = new OcrPdfInput(@"example.pdf");

// Perform OCR
OcrResult result = ocrTesseract.Read(pdfInput);

// Output extracted text to console
Console.WriteLine(result.Text);

Imports IronOcr

' Instantiate IronTesseract
Dim ocrTesseract As New IronTesseract() With {
    .Language = OcrLanguage.EnglishBest
}

' Set secondary language to Russian
ocrTesseract.AddSecondaryLanguage(OcrLanguage.Russian)

' Add PDF
Using pdfInput = New OcrPdfInput("example.pdf")

    ' Perform OCR
    Dim result As OcrResult = ocrTesseract.Read(pdfInput)

    ' Output extracted text to console
    Console.WriteLine(result.Text)
End Using

Customized Languages Reading

Go beyond the built-in language packs by providing your own trained language data. Achieve high accuracy on documents with rare languages, specialized fonts, or unique character sets.

Learn how to:Use Custom Language Files

using IronOcr;

var ocrTesseract = new IronTesseract();
ocrTesseract.UseCustomTesseractLanguageFile("custom_tesseract_files/custom.traineddata");
using var ocrInput = new OcrInput();
ocrInput.LoadImage(@"sample.png");
var ocrResult = ocrTesseract.Read(ocrInput);
Console.WriteLine(ocrResult.Text);

using IronOcr;

var ocrTesseract = new IronTesseract();
ocrTesseract.UseCustomTesseractLanguageFile("custom_tesseract_files/custom.traineddata");
using var ocrInput = new OcrInput();
ocrInput.LoadImage(@"sample.png");
var ocrResult = ocrTesseract.Read(ocrInput);
Console.WriteLine(ocrResult.Text);

Dim ocrTesseract As New IronTesseract()
ocrTesseract.UseCustomTesseractLanguageFile("custom_tesseract_files/custom.traineddata")
Using ocrInput As New OcrInput()
    ocrInput.LoadImage("sample.png")
    Dim ocrResult = ocrTesseract.Read(ocrInput)
    Console.WriteLine(ocrResult.Text)
End Using