IronOCR 和 Tesseract.NET 之间的比较

Install IronOCR

IronOCR supports installation using various methods. We can choose any approach. All methods are safe.

• Using the Visual Studio NuGet Package Manager
• Using the NuGet Package manager Command-Line.
• Direct download from the NuGet website.
• Direct download from the IronOcr website.

Using Visual Studio NuGet Package Manager

We can install the IronOCR library using the NuGet Package manager GUI in Visual Studio. We can access it by clicking on Tools > NuGet Package manager > Manage NuGet Packages for solution.

Go to the Browse tab and search for IronOCR. Select IronOCR from the search results and install it in our project.

Now, we have installed the IronOCR library in our project. It is ready for use in our .NET project.

Using the NuGet Package manager Command-Line

We can use the NuGet Package Manager Console to install the IronOCR library. Go to the Command line, which is usually located below the code file, and then write the following line in the command line and hit Enter.

Install-Package IronOcr

It will begin installing the IronOCR library. After installation, it will be ready to use in our project.

Install the Tesseract.NET SDK

We can install the Tesseract.NET SDK using the NuGet Package Manager. To install the Tesseract.NET SDK, go to Tools > NuGet Package Manager > Manage NuGet Packages for Solution. Go to the Browse tab and search for the Tesseract.NET SDK. Select the Tesseract.NET SDK from the search results and install it. After installation, we can use the Tesseract.NET SDK in our program.

After installation, you can see these three folders in the solution explorer.

These folders contain essential data required by Tesseract to perform OCR. Now we are ready to embed OCR capability in our project.

Test image

This is the image that we will use for testing.

Using the Tesseract.NET SDK

Firstly, we will look at the output generated by the Tesseract.NET SDK for the testing image. Let's take a look at the code:

using Patagames.Ocr;

// Use the OcrApi class to create an API instance for OCR
using (var api = OcrApi.Create())
{
    // Initialize the OCR API with the English language
    api.Init(Patagames.Ocr.Enums.Languages.English);
    // Extract text from the image at the specified path
    string plainText = api.GetTextFromImage(@"C:\Users\Administrator\Desktop\Input.jpg");
    // Print the extracted text to the console
    Console.WriteLine(plainText);
}

using Patagames.Ocr;

// Use the OcrApi class to create an API instance for OCR
using (var api = OcrApi.Create())
{
    // Initialize the OCR API with the English language
    api.Init(Patagames.Ocr.Enums.Languages.English);
    // Extract text from the image at the specified path
    string plainText = api.GetTextFromImage(@"C:\Users\Administrator\Desktop\Input.jpg");
    // Print the extracted text to the console
    Console.WriteLine(plainText);
}

Imports Patagames.Ocr

' Use the OcrApi class to create an API instance for OCR
Using api = OcrApi.Create()
	' Initialize the OCR API with the English language
	api.Init(Patagames.Ocr.Enums.Languages.English)
	' Extract text from the image at the specified path
	Dim plainText As String = api.GetTextFromImage("C:\Users\Administrator\Desktop\Input.jpg")
	' Print the extracted text to the console
	Console.WriteLine(plainText)
End Using

First of all, we will import the Patagames.OCR library for using the Tesseract.NET SDK. After that, we will create an OcrApi by using the Create function. Then, we will set the default language to English using the Init function. Next, we extract plain text from the image using the GetTextFromImage method, and in the parameter, we provide the path of the image files. Then, we write the extracted text to the console.

Next, take a look at the output generated by the Tesseract.NET SDK:

So, this is the output that we get from the Tesseract.NET SDK. At first, it gives errors based on resolution, showing that it works well only for high-resolution images. After the errors, we can see the text extracted from the image. If we compare this text with the image, we will see that it is entirely different. The extracted text has a lot of irrelevant text that makes no sense. Overall, the Tesseract.NET SDK fails this test.

Using IronOCR

Next, we will see the results from IronOCR. Before jumping to the results, we will first look at the code for IronOCR:

using IronOcr;

// Initialize the IronTesseract class for performing OCR
var Ocr = new IronTesseract();
Ocr.Language = OcrLanguage.EnglishBest;

// Use OcrInput to prepare the image for processing
using (var Input = new OcrInput())
{
    Input.AddImage(@"C:\Users\Administrator\Desktop\Input.jpg");
    // Correct the skew and noise in the image
    Input.Deskew();
    Input.DeNoise();
    // Perform OCR and get the result
    var Result = Ocr.Read(Input);
    // Print the recognized text to the console
    Console.WriteLine(Result.Text);
}

using IronOcr;

// Initialize the IronTesseract class for performing OCR
var Ocr = new IronTesseract();
Ocr.Language = OcrLanguage.EnglishBest;

// Use OcrInput to prepare the image for processing
using (var Input = new OcrInput())
{
    Input.AddImage(@"C:\Users\Administrator\Desktop\Input.jpg");
    // Correct the skew and noise in the image
    Input.Deskew();
    Input.DeNoise();
    // Perform OCR and get the result
    var Result = Ocr.Read(Input);
    // Print the recognized text to the console
    Console.WriteLine(Result.Text);
}

Imports IronOcr

' Initialize the IronTesseract class for performing OCR
Private Ocr = New IronTesseract()
Ocr.Language = OcrLanguage.EnglishBest

' Use OcrInput to prepare the image for processing
Using Input = New OcrInput()
	Input.AddImage("C:\Users\Administrator\Desktop\Input.jpg")
	' Correct the skew and noise in the image
	Input.Deskew()
	Input.DeNoise()
	' Perform OCR and get the result
	Dim Result = Ocr.Read(Input)
	' Print the recognized text to the console
	Console.WriteLine(Result.Text)
End Using

In the code above, we import the IronOCR library into our program and then create an object of IronTesseract, which helps start the process. After that, we set the process language to English. Now the actual work can begin. We make the object of OcrInput. Assign the image path to the Input variable using the AddImage function. We use the Deskew function to rotate the image to its actual position, and then use the DeNoise function to remove the noise from the image. This will provide a better outcome. After that, we use the Read function to recognize text and extract it from the testing image. Next, we show the outcome in the console. You can also save the output as a PDF file in the Project file.

Here is the output generated by IronOCR:

If we compare the output, it is the same text that is present on the image. IronOCR extracts text perfectly without any error. IronOCR can extract text from distorted and rotated images. It even works with low resolution images.

IronOCR also supports adding multi-frame images. We can use the "AddMultiFrameTiff" method to do this operation. IronOCR reads every frame in the picture, and every frame is treated as a separate page. Only Tiff images are supported using this method.

using IronOcr;

// Initialize the IronTesseract class for performing OCR
var Ocr = new IronTesseract();

using (var Input = new OcrInput())
{
    // Add a multi-frame TIFF image for OCR processing
    Input.AddMultiFrameTiff("images/multiframe.tiff");

    // Perform OCR and get the result
    var Result = Ocr.Read(Input);
    // Print the recognized text to the console
    Console.WriteLine(Result.Text);
}

using IronOcr;

// Initialize the IronTesseract class for performing OCR
var Ocr = new IronTesseract();

using (var Input = new OcrInput())
{
    // Add a multi-frame TIFF image for OCR processing
    Input.AddMultiFrameTiff("images/multiframe.tiff");

    // Perform OCR and get the result
    var Result = Ocr.Read(Input);
    // Print the recognized text to the console
    Console.WriteLine(Result.Text);
}

Imports IronOcr

' Initialize the IronTesseract class for performing OCR
Private Ocr = New IronTesseract()

Using Input = New OcrInput()
	' Add a multi-frame TIFF image for OCR processing
	Input.AddMultiFrameTiff("images/multiframe.tiff")

	' Perform OCR and get the result
	Dim Result = Ocr.Read(Input)
	' Print the recognized text to the console
	Console.WriteLine(Result.Text)
End Using

Let's take a look at the code for making a searchable PDF:

using IronOcr;

// Initialize the IronTesseract class for performing OCR
var Ocr = new IronTesseract();
using (var Input = new OcrInput())
{
    // Add multiple images for processing
    Input.AddImage(@"images\page1.png");
    Input.AddImage(@"images\page2.bmp");
    Input.AddMultiFrameTiff(@"images\page3.tiff");

    // Deskew the images to correct orientation
    Input.Deskew();

    // Perform OCR and save the result as a searchable PDF
    var Result = Ocr.Read(Input);
    Result.SaveAsSearchablePdf("searchable.pdf");
}

using IronOcr;

// Initialize the IronTesseract class for performing OCR
var Ocr = new IronTesseract();
using (var Input = new OcrInput())
{
    // Add multiple images for processing
    Input.AddImage(@"images\page1.png");
    Input.AddImage(@"images\page2.bmp");
    Input.AddMultiFrameTiff(@"images\page3.tiff");

    // Deskew the images to correct orientation
    Input.Deskew();

    // Perform OCR and save the result as a searchable PDF
    var Result = Ocr.Read(Input);
    Result.SaveAsSearchablePdf("searchable.pdf");
}

Imports IronOcr

' Initialize the IronTesseract class for performing OCR
Private Ocr = New IronTesseract()
Using Input = New OcrInput()
	' Add multiple images for processing
	Input.AddImage("images\page1.png")
	Input.AddImage("images\page2.bmp")
	Input.AddMultiFrameTiff("images\page3.tiff")

	' Deskew the images to correct orientation
	Input.Deskew()

	' Perform OCR and save the result as a searchable PDF
	Dim Result = Ocr.Read(Input)
	Result.SaveAsSearchablePdf("searchable.pdf")
End Using

The SaveAsSearchablePdf function helps to save the files as searchable.

IronOCR Features

IronOCR supports 125 languages. IronOCR also supports QR codes and barcodes of more than 20 types of reading. IronOCR can convert images to Gray Scale for a better outcome. IronOCR can enhance image resolution manually and automatically. It also supports auto-contrast functionality for the best results. IronOCR can export the document in multiple languages and formats such as Searchable PDF, HTML Export, and images of any page. IronOCR supports many input formats such as the following:

• Images (JPG, PNG, GIF, Tiff, BMP)
• Multipage Gif & Tiff
• System.Drawing Objects
• Streams
• PDFs

IronOCR

IronOCR is free for development. It also offers a free trial version for development. IronOCR has a variety of pricing plans for production. You can buy the plan that best matches your needs. There are individual, developer team, and organizational level pricing plans. Prices start from $799 for a Lite plan for one developer and one project. All plans are one-time payments. Users get free updates for one year. It also supports SaaS and OEM coverage. Professional plans are available at $999, while the unlimited plan is priced at $2,999. The unlimited plan includes unlimited developers, projects, and locations.

You can learn more about the pricing plans by following this link. Also, Iron Software currently has a special offer where you can buy a suite of five software packages for the price of just two. These five software packages are all excellent: IronPDF, IronXL, IronOCR, IronBarcode, and IronWebscraper.

The Tesseract.NET SDK

The Tesseract.NET SDK also has a pricing plan. The Tesseract.NET SDK plan starts from $220 for one developer and one project. One important thing to know here is that the pricing plan includes a renewal plan. So, you have to pay either annually or monthly to ensure that the Tesseract.NET SDK is operating in your project. You can learn more about the pricing plan for the Tesseract.NET SDK at this link.