Kofax OmniPage vs IronOCR: .NET OCR Library

Engine Initialization Pattern

Every OmniPage integration begins with an engine lifecycle that spans the application's entire document processing window:

// OmniPage: Engine must be initialized before any operations
// License file must exist at this path on every target machine
using var engine = new OmniPageEngine();
engine.SetLicenseFile(@"C:\Program Files\OmniPage\license.lic");
engine.Initialize();  // Contacts license server; loads 100MB+ of native components

// Configure recognition settings for the document
var settings = new RecognitionSettings
{
    PrimaryLanguage = "English",
    SecondaryLanguages = new[] { "German", "French" },
    AccuracyMode = "Maximum",
    PreserveLayout = true,
    DetectTables = true,
    DespeckleLevel = 2,
    ContrastEnhancement = true,
    AutoRotate = true,
    DeskewImage = true
};

// Document-centric workflow
var document = engine.CreateDocument();
document.AddPage(imagePath);
document.Recognize(settings);
string text = document.GetText();

// Explicit cleanup — omitting this can lock the license
document.Dispose();
engine.Shutdown();

// OmniPage: Engine must be initialized before any operations
// License file must exist at this path on every target machine
using var engine = new OmniPageEngine();
engine.SetLicenseFile(@"C:\Program Files\OmniPage\license.lic");
engine.Initialize();  // Contacts license server; loads 100MB+ of native components

// Configure recognition settings for the document
var settings = new RecognitionSettings
{
    PrimaryLanguage = "English",
    SecondaryLanguages = new[] { "German", "French" },
    AccuracyMode = "Maximum",
    PreserveLayout = true,
    DetectTables = true,
    DespeckleLevel = 2,
    ContrastEnhancement = true,
    AutoRotate = true,
    DeskewImage = true
};

// Document-centric workflow
var document = engine.CreateDocument();
document.AddPage(imagePath);
document.Recognize(settings);
string text = document.GetText();

// Explicit cleanup — omitting this can lock the license
document.Dispose();
engine.Shutdown();

Imports OmniPage

' OmniPage: Engine must be initialized before any operations
' License file must exist at this path on every target machine
Using engine As New OmniPageEngine()
    engine.SetLicenseFile("C:\Program Files\OmniPage\license.lic")
    engine.Initialize()  ' Contacts license server; loads 100MB+ of native components

    ' Configure recognition settings for the document
    Dim settings As New RecognitionSettings With {
        .PrimaryLanguage = "English",
        .SecondaryLanguages = {"German", "French"},
        .AccuracyMode = "Maximum",
        .PreserveLayout = True,
        .DetectTables = True,
        .DespeckleLevel = 2,
        .ContrastEnhancement = True,
        .AutoRotate = True,
        .DeskewImage = True
    }

    ' Document-centric workflow
    Dim document = engine.CreateDocument()
    document.AddPage(imagePath)
    document.Recognize(settings)
    Dim text As String = document.GetText()

    ' Explicit cleanup — omitting this can lock the license
    document.Dispose()
    engine.Shutdown()
End Using

This pattern must be reproduced for every integration point: ASP.NET request handlers, Windows services, batch processing jobs, and unit tests all need to manage the engine lifecycle. On a floating license configuration, forgetting Shutdown() in an error path locks a license seat for every other process until the server restarts.

Detailed Feature Comparison

Kofax OmniPage Approach

The OmniPage acquisition process follows a fixed sequence that no developer can shortcut:

OmniPage deployment steps (from the kofax-enterprise-ocr.cs source):

1.  Complete sales process (4–12 weeks)
2.  Receive SDK installer from Tungsten
3.  Install SDK on development machines
4.  Configure license files (per-machine or floating)
5.  Set up license server (if using network licensing)
6.  Install runtime components on production servers
7.  Deploy license files to production
8.  Configure firewall for license server communication
9.  Set up monitoring for license availability
10. Document shutdown procedures for license release

Steps 5, 8, and 9 are not developer tasks — they require coordination with infrastructure and security teams. Step 7 means every production deployment needs the .lic file present at a hardcoded path. Step 10 exists because forgetting Shutdown() in any code path locks a floating license seat indefinitely.

The per-page licensing model adds another layer of operational complexity. Usage reporting flows to a license server, billing reconciliation happens monthly or quarterly, and any unexpected spike in document volume (a new client onboarded, a backlog processed) generates an overage invoice that nobody budgeted for.

IronOCR Approach

// Step 1: Install
// dotnet add package IronOcr

// Step 2: Configure license (one line at startup)
IronOcr.License.LicenseKey = "YOUR-LICENSE-KEY";

// Step 3: Read a document
var text = new IronTesseract().Read("document.jpg").Text;

// Step 1: Install
// dotnet add package IronOcr

// Step 2: Configure license (one line at startup)
IronOcr.License.LicenseKey = "YOUR-LICENSE-KEY";

// Step 3: Read a document
var text = new IronTesseract().Read("document.jpg").Text;

' Step 1: Install
' dotnet add package IronOcr

' Step 2: Configure license (one line at startup)
IronOcr.License.LicenseKey = "YOUR-LICENSE-KEY"

' Step 3: Read a document
Dim text As String = (New IronTesseract()).Read("document.jpg").Text

No installer. No DLL references. No license file on disk. No license server. No firewall rules. No shutdown procedure. The license key is a string — store it in an environment variable, appsettings.json, or Azure Key Vault. Changing deployment targets (from a Windows VM to a Linux Docker container, for example) requires no license reconfiguration.

The IronTesseract setup guide covers full configuration options including environment variable–based key injection, which removes license strings from source code entirely.

Kofax OmniPage Approach

OmniPage's installer-based distribution model creates friction at every stage of a modern deployment pipeline. Building a Docker container requires the custom SDK installer to run inside the image, the license file to be baked in or mounted at runtime, and engine.Shutdown() to execute before the container stops. A Kubernetes pod restart that does not cleanly shut down the OmniPage engine can leave floating license seats locked until the license server's checkout timeout expires (typically 30–60 minutes).

In CI/CD pipelines, every agent that runs integration tests needs the SDK installed and a valid license file available. Test parallelism is limited by the number of licensed seats. On OmniPage's per-page model, automated test runs consume billable pages.

The namespace Kofax.OmniPage.CSDK is referenced via manually added DLL paths, not a package manager. Updating to a new SDK version means re-running the installer on every development machine, build agent, and production server — not incrementing a version number in a .csproj file.

IronOCR Approach

<PackageReference Include="IronOcr" Version="2024.x.x" />

<PackageReference Include="IronOcr" Version="2024.x.x" />

# Docker: no installer, no license file mount required
FROM mcr.microsoft.com/dotnet/aspnet:8.0
RUN apt-get update && apt-get install -y libgdiplus
COPY --from=build /app/publish /app
WORKDIR /app
ENTRYPOINT ["dotnet", "YourApp.dll"]

The Docker deployment guide covers the one Linux dependency (libgdiplus for image rendering) and nothing else. The same NuGet package runs on Linux, AWS Lambda, and Azure App Service without platform-specific configuration. CI/CD pipelines restore the package via dotnet restore the same way every other dependency restores — no installer steps, no license file management, no seat count constraints on test parallelism.

Kofax OmniPage Approach

OmniPage's license validation sequence creates multiple failure modes that have nothing to do with OCR:

// OmniPage: License validation at engine startup
// Each of these can fail independently
public static void InitializeWithLicense(string licensePath)
{
    // Failure mode 1: File missing (deployment error, path misconfiguration)
    if (!File.Exists(licensePath))
        throw new LicenseException("License file not found");

    // Failure mode 2: File permissions (service account lacks read access)
    try { using var stream = File.OpenRead(licensePath); }
    catch (UnauthorizedAccessException)
    {
        throw new LicenseException("Cannot read license file — check permissions");
    }

    // Failure mode 3: License server unreachable (network partition, server restart)
    var engine = new OmniPageEngine();
    engine.SetLicenseFile(licensePath);

    try
    {
        engine.Initialize(); // Network call to license server
    }
    catch (LicenseValidationException ex)
    {
        // Could be: expired, invalid hardware, concurrent seat limit exceeded,
        // license server unreachable, or maintenance window
        throw new LicenseException($"License validation failed: {ex.Message}");
    }
}

// OmniPage: License validation at engine startup
// Each of these can fail independently
public static void InitializeWithLicense(string licensePath)
{
    // Failure mode 1: File missing (deployment error, path misconfiguration)
    if (!File.Exists(licensePath))
        throw new LicenseException("License file not found");

    // Failure mode 2: File permissions (service account lacks read access)
    try { using var stream = File.OpenRead(licensePath); }
    catch (UnauthorizedAccessException)
    {
        throw new LicenseException("Cannot read license file — check permissions");
    }

    // Failure mode 3: License server unreachable (network partition, server restart)
    var engine = new OmniPageEngine();
    engine.SetLicenseFile(licensePath);

    try
    {
        engine.Initialize(); // Network call to license server
    }
    catch (LicenseValidationException ex)
    {
        // Could be: expired, invalid hardware, concurrent seat limit exceeded,
        // license server unreachable, or maintenance window
        throw new LicenseException($"License validation failed: {ex.Message}");
    }
}

Imports System.IO

' OmniPage: License validation at engine startup
' Each of these can fail independently
Public Shared Sub InitializeWithLicense(licensePath As String)
    ' Failure mode 1: File missing (deployment error, path misconfiguration)
    If Not File.Exists(licensePath) Then
        Throw New LicenseException("License file not found")
    End If

    ' Failure mode 2: File permissions (service account lacks read access)
    Try
        Using stream = File.OpenRead(licensePath)
        End Using
    Catch ex As UnauthorizedAccessException
        Throw New LicenseException("Cannot read license file — check permissions")
    End Try

    ' Failure mode 3: License server unreachable (network partition, server restart)
    Dim engine As New OmniPageEngine()
    engine.SetLicenseFile(licensePath)

    Try
        engine.Initialize() ' Network call to license server
    Catch ex As LicenseValidationException
        ' Could be: expired, invalid hardware, concurrent seat limit exceeded,
        ' license server unreachable, or maintenance window
        Throw New LicenseException($"License validation failed: {ex.Message}")
    End Try
End Sub

A network partition between an application server and the license server fails every engine.Initialize() call until the partition resolves, regardless of whether the license was previously validated on that machine. Per-page licensing adds a fourth failure mode: exhausted page quota mid-batch.

IronOCR Approach

// One line at application startup
IronOcr.License.LicenseKey = "YOUR-LICENSE-KEY";

// Optional: verify license status
bool isLicensed = IronOcr.License.IsLicensed;

// Works offline — no license server, no network calls at runtime
var text = new IronTesseract().Read("document.jpg").Text;

// One line at application startup
IronOcr.License.LicenseKey = "YOUR-LICENSE-KEY";

// Optional: verify license status
bool isLicensed = IronOcr.License.IsLicensed;

// Works offline — no license server, no network calls at runtime
var text = new IronTesseract().Read("document.jpg").Text;

Imports IronOcr

' One line at application startup
IronOcr.License.LicenseKey = "YOUR-LICENSE-KEY"

' Optional: verify license status
Dim isLicensed As Boolean = IronOcr.License.IsLicensed

' Works offline — no license server, no network calls at runtime
Dim text As String = New IronTesseract().Read("document.jpg").Text

IronOCR validates the license key locally. No network call occurs during OCR operations. A production server that loses internet access after startup continues processing documents without interruption. The licensing page covers all tiers: $999 Lite for single-developer single-project use through $5,999 Unlimited for teams with no developer or project caps.

The key can come from an environment variable (IRONOCR_LICENSE_KEY) with no code changes, making it straightforward to use different keys across development, staging, and production without modifying deployed binaries.

Kofax OmniPage Approach

The OmniPage ownership chain since 2001: Caere → Nuance → Kofax → Tungsten Automation. Each acquisition introduced a transition period where documentation URLs broke, support channels changed, partner networks restructured, and enterprise license agreements required renegotiation under new terms. The January 2026 release of OmniPage Capture SDK 2025.3 (which added Linux support) confirms active development, but the Tungsten Automation rebrand is less than two years old and the product roadmap documentation was listed as "under review" during that transition.

For teams buying 3–5 year enterprise agreements, the question is not whether OmniPage works today — it does — but whether Tungsten Automation's strategic priorities in 2028 align with the product's current roadmap. Enterprise software acquisitions frequently result in maintenance mode status for acquired products when the acquirer's roadmap priorities shift toward their own platform components.

The documentation migration alone creates operational friction: Kofax-era support tickets, documentation bookmarks, and community forum posts referencing old URL structures no longer resolve correctly, which adds friction to the support experience at exactly the moment developers need help most (during incidents and complex integrations).

IronOCR Approach

Iron Software is a focused developer tools company whose entire product line is .NET libraries. IronOCR, IronPDF, IronBarcode, and related products are the company's core business — not an acquired product being absorbed into a larger enterprise automation platform. Release history shows consistent updates aligned with the .NET release cadence (supporting .NET 8, .NET 9, and targeting .NET 10 compatibility). The documentation hub and tutorials are maintained under stable URLs with version-specific content.

The Budget Ceiling Gets Hit

An enterprise team running OmniPage for contract processing hits a natural ceiling when the document volume grows and per-page licensing costs scale with it. Runtime fees accumulate annually on top of the SDK license and maintenance. The business case for a one-time $2,999 IronOCR Professional license becomes straightforward: the perpetual license pays for itself quickly compared to ongoing per-page fees. Teams in this position typically run a parallel accuracy validation across 1,000 representative documents, find the accuracy gap between OmniPage and IronOCR to be under 1% on their standard invoice and contract content, and complete the migration in under two weeks.

The Procurement Timeline Blocks Product Delivery

A startup or mid-size company building a document digitization feature discovers that the OCR vendor requiring 4–12 weeks of sales engagement will miss their product launch date. The product manager does not have 8 weeks for procurement. IronOCR installs from NuGet in 30 seconds; a license key from the IronOCR product page is self-service. The feature ships. This scenario is not hypothetical — it is the most common reason development teams document when they explain their technology choices to engineering leadership after the fact.

The Deployment Topology Changes

A team running OmniPage on Windows servers decides to migrate to containerized deployment on Kubernetes. The OmniPage SDK installer does not fit neatly into a Docker build pipeline, the license file needs to be mounted or baked into the image (both have security implications), and container restarts require handling the engine shutdown/startup lifecycle cleanly. Scaling horizontally to 10 containers requires 10 floating license seats or 10 node-locked licenses. IronOCR's NuGet deployment model, environment variable–based license keys, and offline license validation make containerized deployment straightforward. The Docker deployment documentation covers the complete setup, and horizontal scaling requires no additional licensing actions — the Unlimited license covers unlimited deployments.

The ICR Requirement Disappears

Many teams initially adopt OmniPage because a stakeholder requirement listed "handwriting recognition" as a feature. When that requirement gets scoped — the actual need turns out to be printed forms with checkboxes, not free-form handwritten fields — the ICR justification for the enterprise pricing evaporates. IronOCR handles checkbox detection via its OMR-adjacent capabilities and structured data extraction at a fraction of the cost. Teams that reassess their actual document corpus frequently find that 95%+ of their volume consists of printed PDFs and scanned invoices where OmniPage's ICR advantage is never exercised.

Tungsten Acquisition Uncertainty Triggers a Risk Review

Enterprise procurement teams conduct periodic vendor risk reviews. When a tool provider has changed ownership four times in 25 years, the most recent rebrand is under two years old, and the product roadmap documentation was marked "under review" during the transition, some teams choose to reduce vendor concentration risk by moving a workload to a stable, focused developer tools provider. This is a business decision as much as a technical one — IronOCR's OCR accuracy on standard business documents is competitive with OmniPage's, and the migration removes an enterprise contract renewal discussion from the annual budget cycle.

Engine Lifecycle to Stateless Calls

OmniPage integrations are built around a long-lived OmniPageEngine instance that must be initialized at startup and shut down at process exit. IronOCR has no equivalent lifecycle. The IronTesseract class is instantiated per call or shared as a long-lived service — both patterns work.

// OmniPage pattern: service class with engine lifecycle
public class KofaxDocumentService : IDisposable
{
    private OmniPageEngine _engine;

    public KofaxDocumentService(string licensePath)
    {
        _engine = new OmniPageEngine();
        _engine.SetLicenseFile(licensePath);
        _engine.Initialize();
    }

    public string ProcessDocument(string imagePath)
    {
        var document = _engine.CreateDocument();
        document.AddPage(imagePath);
        document.Recognize(new RecognitionSettings { Language = "English" });
        string text = document.GetText();
        document.Dispose();  // Must not be forgotten
        return text;
    }

    public void Dispose()
    {
        _engine.Shutdown();  // Must not be forgotten
    }
}

// IronOCR equivalent: no lifecycle management needed
public class IronOcrDocumentService
{
    private readonly IronTesseract _ocr;

    public IronOcrDocumentService()
    {
        _ocr = new IronTesseract();
        _ocr.Language = OcrLanguage.English;
    }

    public string ProcessDocument(string imagePath)
    {
        using var input = new OcrInput();
        input.LoadImage(imagePath);
        return _ocr.Read(input).Text;
    }
    // No Dispose — no unmanaged resources to release
}

// OmniPage pattern: service class with engine lifecycle
public class KofaxDocumentService : IDisposable
{
    private OmniPageEngine _engine;

    public KofaxDocumentService(string licensePath)
    {
        _engine = new OmniPageEngine();
        _engine.SetLicenseFile(licensePath);
        _engine.Initialize();
    }

    public string ProcessDocument(string imagePath)
    {
        var document = _engine.CreateDocument();
        document.AddPage(imagePath);
        document.Recognize(new RecognitionSettings { Language = "English" });
        string text = document.GetText();
        document.Dispose();  // Must not be forgotten
        return text;
    }

    public void Dispose()
    {
        _engine.Shutdown();  // Must not be forgotten
    }
}

// IronOCR equivalent: no lifecycle management needed
public class IronOcrDocumentService
{
    private readonly IronTesseract _ocr;

    public IronOcrDocumentService()
    {
        _ocr = new IronTesseract();
        _ocr.Language = OcrLanguage.English;
    }

    public string ProcessDocument(string imagePath)
    {
        using var input = new OcrInput();
        input.LoadImage(imagePath);
        return _ocr.Read(input).Text;
    }
    // No Dispose — no unmanaged resources to release
}

Imports System

' OmniPage pattern: service class with engine lifecycle
Public Class KofaxDocumentService
    Implements IDisposable

    Private _engine As OmniPageEngine

    Public Sub New(licensePath As String)
        _engine = New OmniPageEngine()
        _engine.SetLicenseFile(licensePath)
        _engine.Initialize()
    End Sub

    Public Function ProcessDocument(imagePath As String) As String
        Dim document = _engine.CreateDocument()
        document.AddPage(imagePath)
        document.Recognize(New RecognitionSettings With {.Language = "English"})
        Dim text As String = document.GetText()
        document.Dispose()  ' Must not be forgotten
        Return text
    End Function

    Public Sub Dispose() Implements IDisposable.Dispose
        _engine.Shutdown()  ' Must not be forgotten
    End Sub
End Class

' IronOCR equivalent: no lifecycle management needed
Public Class IronOcrDocumentService

    Private ReadOnly _ocr As IronTesseract

    Public Sub New()
        _ocr = New IronTesseract()
        _ocr.Language = OcrLanguage.English
    End Sub

    Public Function ProcessDocument(imagePath As String) As String
        Using input As New OcrInput()
            input.LoadImage(imagePath)
            Return _ocr.Read(input).Text
        End Using
    End Function
    ' No Dispose — no unmanaged resources to release
End Class

The using var input = new OcrInput() pattern handles resource cleanup for the input data. The IronTesseract instance itself carries no unmanaged state that needs explicit teardown.

PDF Processing Without Separate Module Licensing

OmniPage PDF processing typically requires a specific output format configuration and, depending on the SDK edition, a separate PDF module license. IronOCR's PDF input support is built into the base NuGet package. Scanned PDFs, native PDFs, and password-protected PDFs all use the same API surface.

// Extract text from a scanned PDF — no extra module or license
using var input = new OcrInput();
input.LoadPdf("scanned-contract.pdf");
var result = new IronTesseract().Read(input);
Console.WriteLine(result.Text);

// Create a searchable PDF from a scanned-only PDF
result.SaveAsSearchablePdf("contract-searchable.pdf");

// Process specific pages from a large PDF
using var input = new OcrInput();
input.LoadPdfPages("large-report.pdf", 1, 10);  // Pages 1–10 only
var result = new IronTesseract().Read(input);

// Extract text from a scanned PDF — no extra module or license
using var input = new OcrInput();
input.LoadPdf("scanned-contract.pdf");
var result = new IronTesseract().Read(input);
Console.WriteLine(result.Text);

// Create a searchable PDF from a scanned-only PDF
result.SaveAsSearchablePdf("contract-searchable.pdf");

// Process specific pages from a large PDF
using var input = new OcrInput();
input.LoadPdfPages("large-report.pdf", 1, 10);  // Pages 1–10 only
var result = new IronTesseract().Read(input);

Imports IronOcr

' Extract text from a scanned PDF — no extra module or license
Using input As New OcrInput()
    input.LoadPdf("scanned-contract.pdf")
    Dim result = New IronTesseract().Read(input)
    Console.WriteLine(result.Text)
End Using

' Create a searchable PDF from a scanned-only PDF
result.SaveAsSearchablePdf("contract-searchable.pdf")

' Process specific pages from a large PDF
Using input As New OcrInput()
    input.LoadPdfPages("large-report.pdf", 1, 10)  ' Pages 1–10 only
    Dim result = New IronTesseract().Read(input)
End Using

The searchable PDF output guide covers the text layer embedding that makes scanned PDFs indexable in document management systems — a common requirement in the same workflows where OmniPage is deployed.

Language Pack Distribution

OmniPage language dictionaries are part of the SDK installation and load at engine startup whether the current document needs them or not. IronOCR language packs are separate NuGet packages; only languages installed and referenced are loaded.

// Add language packs as NuGet packages, not installer components
// dotnet add package IronOcr.Languages.German
// dotnet add package IronOcr.Languages.French

var ocr = new IronTesseract();
ocr.Language = OcrLanguage.English;
ocr.AddSecondaryLanguage(OcrLanguage.German);
ocr.AddSecondaryLanguage(OcrLanguage.French);

using var input = new OcrInput();
input.LoadImage("multilingual-document.jpg");
var result = ocr.Read(input);

// Add language packs as NuGet packages, not installer components
// dotnet add package IronOcr.Languages.German
// dotnet add package IronOcr.Languages.French

var ocr = new IronTesseract();
ocr.Language = OcrLanguage.English;
ocr.AddSecondaryLanguage(OcrLanguage.German);
ocr.AddSecondaryLanguage(OcrLanguage.French);

using var input = new OcrInput();
input.LoadImage("multilingual-document.jpg");
var result = ocr.Read(input);

Imports IronOcr

' Add language packs as NuGet packages, not installer components
' dotnet add package IronOcr.Languages.German
' dotnet add package IronOcr.Languages.French

Dim ocr As New IronTesseract()
ocr.Language = OcrLanguage.English
ocr.AddSecondaryLanguage(OcrLanguage.German)
ocr.AddSecondaryLanguage(OcrLanguage.French)

Using input As New OcrInput()
    input.LoadImage("multilingual-document.jpg")
    Dim result = ocr.Read(input)
End Using

The multiple languages guide covers language combination patterns. Language packs restore via dotnet restore in CI/CD pipelines with no installer involvement. The full languages catalog lists all 125+ available packs.

Preprocessing: Settings Object vs. Method Pipeline

OmniPage configures preprocessing through a RecognitionSettings or PreprocessingSettings object passed to the engine. IronOCR exposes preprocessing as a method pipeline on OcrInput. The behavior is equivalent; the invocation model differs.

// OmniPage: preprocessing embedded in RecognitionSettings
var preprocessSettings = new PreprocessingSettings
{
    AutoRotate = true,
    Deskew = true,
    DespeckleLevel = 2,
    ContrastEnhancement = true,
    NoiseReduction = true
};
var recognitionSettings = new RecognitionSettings
{
    Language = "English",
    Preprocessing = preprocessSettings
};

// IronOCR: preprocessing as method pipeline on OcrInput
using var input = new OcrInput();
input.LoadImage(imagePath);
input.Deskew();
input.DeNoise();
input.Contrast();
input.Binarize();
input.EnhanceResolution(300);
var result = new IronTesseract().Read(input);

// OmniPage: preprocessing embedded in RecognitionSettings
var preprocessSettings = new PreprocessingSettings
{
    AutoRotate = true,
    Deskew = true,
    DespeckleLevel = 2,
    ContrastEnhancement = true,
    NoiseReduction = true
};
var recognitionSettings = new RecognitionSettings
{
    Language = "English",
    Preprocessing = preprocessSettings
};

// IronOCR: preprocessing as method pipeline on OcrInput
using var input = new OcrInput();
input.LoadImage(imagePath);
input.Deskew();
input.DeNoise();
input.Contrast();
input.Binarize();
input.EnhanceResolution(300);
var result = new IronTesseract().Read(input);

Imports IronOcr

' OmniPage: preprocessing embedded in RecognitionSettings
Dim preprocessSettings As New PreprocessingSettings With {
    .AutoRotate = True,
    .Deskew = True,
    .DespeckleLevel = 2,
    .ContrastEnhancement = True,
    .NoiseReduction = True
}
Dim recognitionSettings As New RecognitionSettings With {
    .Language = "English",
    .Preprocessing = preprocessSettings
}

' IronOCR: preprocessing as method pipeline on OcrInput
Using input As New OcrInput()
    input.LoadImage(imagePath)
    input.Deskew()
    input.DeNoise()
    input.Contrast()
    input.Binarize()
    input.EnhanceResolution(300)
    Dim result = New IronTesseract().Read(input)
End Using

The image quality correction guide covers all available filters. For documents where the default automatic preprocessing is sufficient, no explicit calls are needed — IronOCR applies deskew, noise reduction, and contrast enhancement automatically.