Windows用Tesseract Ocr（コード例のチュートリアル）

Installer Language

This is just the language for the dialog boxes and help information. If we want to, we can run Tesseract OCR for Windows in multiple languages:

Installer language for Tesseract OCR for Windows

Tesseract OCR Setup

The setup screen recommends that all other applications are closed before continuing with the installation.

The Tesseract OCR for Windows installation screen.

Choose Install Location

Next, we'll choose the installation location. Before proceeding to the next step, make sure to copy the install location to a .txt file. We will need to add the installation location to our machine's environment variables once the installation is complete.

Choose the installation location.

Choose Components

By default, the ScrollView, Training Tools, Shortcuts creation, and Language data are all selected. Unless you have a specific reason not to install these, we will want to keep all of these selected.

Default Tesseract OCR for Windows installation components.

If we scroll down and expand the ‘Additional script data’, we will see that we have the option to download and install additional script data. This can be helpful in improving the accuracy of text extraction from certain scripted languages. It’s up to you if you want to install these.

Optional script installation components.

Choose the Start Menu Folder

In the last step of the installation, we’ll be asked to choose the start menu folder for Tesseract OCR for Windows shortcuts. I’ve left mine set to the default name: ‘Tesseract-OCR’.

Choose the start menu folder for the Tesseract OCR for Windows shortcuts.

After we click install, Tesseract OCR for Windows will begin installing. Our next step is to add the installation path to our machine’s environment variables.

Control Panel

To add the installation location to our environment variables, go to the Start menu and search for 'environment variables'. You should see a result to edit the system environment variables. If you don’t, you can always use the following steps: Start menu > Control Panel > Edit the system environment variables.

Searching for ‘environment variables’

System Properties

When presented with the ‘System Properties’ dialog box, we’ll want to make sure the Advanced tab is clicked, then click the Environment Variables button towards the bottom right of the screen.

Environment Variables

Under system variables, we will click the Edit button.

When presented with the "Edit environment variable" screen, click the New button, and paste in your Tesseract OCR installation path that we copied earlier in Step 2. Once you’ve done this, click the ‘OK‘ button.

Add Tesseract OCR for Windows Installation Directory to Environment Variables

That’s it! Now that we’ve run the .exe installer and added the Tesseract OCR for Windows install location to our environment variables, we can test that our installation is working by running Tesseract on a test image.

Install DLL

Download the IronOcr DLL directly to your machine.

Install NuGet

Alternatively, you can install it through NuGet with the following command:

Install-Package IronOcr

Set your IronOCR license key using code

Add this code to the startup of your application before IronOCR is used.

IronOcr.Installation.LicenseKey = "IRONOCR-MYLICENSE-KEY-1EF01";

IronOcr.Installation.LicenseKey = "IRONOCR-MYLICENSE-KEY-1EF01";

IronOcr.Installation.LicenseKey = "IRONOCR-MYLICENSE-KEY-1EF01"

Code Example for .NET OCR Usage — Extract Text from Images in C#

Use NuGet Package Manager to install the IronOCR NuGet Package into your Visual Studio solution.

// PM > Install-Package IronOcr
// using IronOcr;

var Ocr = new IronTesseract();

// Set the recognition language to English
Ocr.Language = OcrLanguage.English;

using (var Input = new OcrInput())
{
    // Add an example image to the OCR input
    Input.Add(@"img\example.tiff");

    // Optional: Clean the image before processing
    // Input.DeNoise();
    // Input.Deskew();

    // Read the text from the image
    IronOcr.OcrResult result = Ocr.Read(Input);

    // Output the recognized text
    Console.WriteLine(result.Text);

    // Explore the OcrResult using IntelliSense
}

// PM > Install-Package IronOcr
// using IronOcr;

var Ocr = new IronTesseract();

// Set the recognition language to English
Ocr.Language = OcrLanguage.English;

using (var Input = new OcrInput())
{
    // Add an example image to the OCR input
    Input.Add(@"img\example.tiff");

    // Optional: Clean the image before processing
    // Input.DeNoise();
    // Input.Deskew();

    // Read the text from the image
    IronOcr.OcrResult result = Ocr.Read(Input);

    // Output the recognized text
    Console.WriteLine(result.Text);

    // Explore the OcrResult using IntelliSense
}

' PM > Install-Package IronOcr
' using IronOcr;

Dim Ocr = New IronTesseract()

' Set the recognition language to English
Ocr.Language = OcrLanguage.English

Using Input = New OcrInput()
	' Add an example image to the OCR input
	Input.Add("img\example.tiff")

	' Optional: Clean the image before processing
	' Input.DeNoise();
	' Input.Deskew();

	' Read the text from the image
	Dim result As IronOcr.OcrResult = Ocr.Read(Input)

	' Output the recognized text
	Console.WriteLine(result.Text)

	' Explore the OcrResult using IntelliSense
End Using

Tesseract 5 API in IronOCR Tesseract

To date, IronTesseract is the only known implementation of Tesseract 5 for .NET Framework or Core.

// using IronOcr;

var Ocr = new IronTesseract(); // nothing to configure

using (var Input = new OcrInput(@"images\image.png"))
{
    var result = Ocr.Read(Input);

    // Output the recognized text
    Console.WriteLine(result.Text);
}

// using IronOcr;

var Ocr = new IronTesseract(); // nothing to configure

using (var Input = new OcrInput(@"images\image.png"))
{
    var result = Ocr.Read(Input);

    // Output the recognized text
    Console.WriteLine(result.Text);
}

' using IronOcr;

Dim Ocr = New IronTesseract() ' nothing to configure

Using Input = New OcrInput("images\image.png")
	Dim result = Ocr.Read(Input)

	' Output the recognized text
	Console.WriteLine(result.Text)
End Using

Tesseract 4 API in IronOCR Tesseract

// using IronOcr;

var Ocr = new IronTesseract();

// Specify the version of Tesseract
Ocr.Configuration.TesseractVersion = TesseractVersion.Tesseract4;

using (var Input = new OcrInput(@"images\image.png"))
{
    var result = Ocr.Read(Input);

    // Output the recognized text
    Console.WriteLine(result.Text);
}

// using IronOcr;

var Ocr = new IronTesseract();

// Specify the version of Tesseract
Ocr.Configuration.TesseractVersion = TesseractVersion.Tesseract4;

using (var Input = new OcrInput(@"images\image.png"))
{
    var result = Ocr.Read(Input);

    // Output the recognized text
    Console.WriteLine(result.Text);
}

' using IronOcr;

Dim Ocr = New IronTesseract()

' Specify the version of Tesseract
Ocr.Configuration.TesseractVersion = TesseractVersion.Tesseract4

Using Input = New OcrInput("images\image.png")
	Dim result = Ocr.Read(Input)

	' Output the recognized text
	Console.WriteLine(result.Text)
End Using

ACCURACY

IMAGE COMPATIBILITY

PERFORMANCE

API

LANGUAGE