OCRツール Windows OCRエンジン対Tesseract:詳細な比較 Kannapat Udonpant 更新日:7月 28, 2025 Download IronOCR NuGet Download テキストの検索と置換 テキストと画像のスタンプ Start Free Trial Copy for LLMs Copy for LLMs Copy page as Markdown for LLMs Open in ChatGPT Ask ChatGPT about this page Open in Gemini Ask Gemini about this page Open in Grok Ask Grok about this page Open in Perplexity Ask Perplexity about this page Share Share on Facebook Share on X (Twitter) Share on LinkedIn Copy URL Email article In today's digital age, Optical Character Recognition (OCR) technology has become integral to various industries, enabling the conversion of images and scanned documents into editable and searchable text. Among the many OCR software available, such as Google Cloud Vision (Cloud Vision API), Adobe Acrobat Pro DC, ABBYY Finereader, Windows OCR Engine, Tesseract, and IronOCR stand out as prominent contenders, each offering unique features and capabilities to aid document analysis. This article aims to provide a comprehensive comparative analysis of these three OCR engines, evaluating their accuracy, performance, and ease of integration. 1. Introduction to OCR Engines OCR engines are software tools designed to recognize and extract plain text from images, PDFs, and other scanned documents. They employ sophisticated algorithms and machine learning techniques to accurately identify characters and convert them into a machine-readable text file. Windows OCR Engine, Tesseract, and IronOCR represent three widely used OCR solutions, each with its strengths and applications. 2. Windows OCR Engine The Windows OCR Engine, integrated into the Windows operating system, offers a convenient and user-friendly solution for extracting text from input images and scanned documents. Leveraging advanced image processing techniques, it can accurately recognize text in various languages and font styles. The Windows OCR Engine is accessible through the Windows Runtime API, enabling seamless integration into Windows applications with the capabilities of a command-line tool. 2.1 Key Features of Windows OCR Engine Language Support: The Windows OCR Engine supports many languages, making it suitable for multilingual documents. Image Processing: It employs sophisticated image processing algorithms to enhance printed text recognition accuracy, even in low-quality images. Integration with Windows Applications: The Windows OCR Engine seamlessly integrates with Windows applications, allowing developers to fully incorporate OCR capabilities into their software. 2.2 Code Example using System; using System.IO; using System.Text; using System.Threading.Tasks; using Windows.Graphics.Imaging; using Windows.Media.Ocr; class Program { static async Task Main(string[] args) { // Provide the path to the image file string imagePath = "sample.png"; try { // Call the ExtractText method to extract text from the image string extractedText = await ExtractText(imagePath); // Display the extracted text Console.WriteLine("Extracted Text:"); Console.WriteLine(extractedText); } catch (Exception ex) { Console.WriteLine("An error occurred: " + ex.Message); } } public static async Task<string> ExtractText(string image) { // Initialize StringBuilder to store extracted text StringBuilder text = new StringBuilder(); try { // Open the image file stream using (var fileStream = File.OpenRead(image)) { // Create a BitmapDecoder from the image file stream var bmpDecoder = await BitmapDecoder.CreateAsync(fileStream.AsRandomAccessStream()); // Get the software bitmap from the decoder var softwareBmp = await bmpDecoder.GetSoftwareBitmapAsync(); // Create an OCR engine from user profile languages var ocrEngine = OcrEngine.TryCreateFromUserProfileLanguages(); // Recognize text from the software bitmap var ocrResult = await ocrEngine.RecognizeAsync(softwareBmp); // Append each line of recognized text to the StringBuilder foreach (var line in ocrResult.Lines) { text.AppendLine(line.Text); } } } catch (Exception ex) { Console.WriteLine("Error during OCR process: " + ex.Message); } // Return the extracted text return text.ToString(); } } using System; using System.IO; using System.Text; using System.Threading.Tasks; using Windows.Graphics.Imaging; using Windows.Media.Ocr; class Program { static async Task Main(string[] args) { // Provide the path to the image file string imagePath = "sample.png"; try { // Call the ExtractText method to extract text from the image string extractedText = await ExtractText(imagePath); // Display the extracted text Console.WriteLine("Extracted Text:"); Console.WriteLine(extractedText); } catch (Exception ex) { Console.WriteLine("An error occurred: " + ex.Message); } } public static async Task<string> ExtractText(string image) { // Initialize StringBuilder to store extracted text StringBuilder text = new StringBuilder(); try { // Open the image file stream using (var fileStream = File.OpenRead(image)) { // Create a BitmapDecoder from the image file stream var bmpDecoder = await BitmapDecoder.CreateAsync(fileStream.AsRandomAccessStream()); // Get the software bitmap from the decoder var softwareBmp = await bmpDecoder.GetSoftwareBitmapAsync(); // Create an OCR engine from user profile languages var ocrEngine = OcrEngine.TryCreateFromUserProfileLanguages(); // Recognize text from the software bitmap var ocrResult = await ocrEngine.RecognizeAsync(softwareBmp); // Append each line of recognized text to the StringBuilder foreach (var line in ocrResult.Lines) { text.AppendLine(line.Text); } } } catch (Exception ex) { Console.WriteLine("Error during OCR process: " + ex.Message); } // Return the extracted text return text.ToString(); } } Imports System Imports System.IO Imports System.Text Imports System.Threading.Tasks Imports Windows.Graphics.Imaging Imports Windows.Media.Ocr Friend Class Program Shared Async Function Main(ByVal args() As String) As Task ' Provide the path to the image file Dim imagePath As String = "sample.png" Try ' Call the ExtractText method to extract text from the image Dim extractedText As String = Await ExtractText(imagePath) ' Display the extracted text Console.WriteLine("Extracted Text:") Console.WriteLine(extractedText) Catch ex As Exception Console.WriteLine("An error occurred: " & ex.Message) End Try End Function Public Shared Async Function ExtractText(ByVal image As String) As Task(Of String) ' Initialize StringBuilder to store extracted text Dim text As New StringBuilder() Try ' Open the image file stream Using fileStream = File.OpenRead(image) ' Create a BitmapDecoder from the image file stream Dim bmpDecoder = Await BitmapDecoder.CreateAsync(fileStream.AsRandomAccessStream()) ' Get the software bitmap from the decoder Dim softwareBmp = Await bmpDecoder.GetSoftwareBitmapAsync() ' Create an OCR engine from user profile languages Dim ocrEngine = OcrEngine.TryCreateFromUserProfileLanguages() ' Recognize text from the software bitmap Dim ocrResult = Await ocrEngine.RecognizeAsync(softwareBmp) ' Append each line of recognized text to the StringBuilder For Each line In ocrResult.Lines text.AppendLine(line.Text) Next line End Using Catch ex As Exception Console.WriteLine("Error during OCR process: " & ex.Message) End Try ' Return the extracted text Return text.ToString() End Function End Class $vbLabelText $csharpLabel 2.2.1 Output 3. Tesseract Tesseract, an open-source OCR engine developed by Google, has gained widespread popularity for its accuracy and versatility. It supports over 100 languages and can process various image formats, including TIFF, JPEG, and PNG. Tesseract OCR Engine employs deep learning algorithms and neural networks to achieve high levels of text recognition accuracy, making it suitable for a wide range of applications. 3.1 Key Features of Tesseract Language Support: The Tesseract engine supports over 100 languages, including complex scripts such as Arabic and Chinese. Image Preprocessing: It offers extensive image preprocessing capabilities, including deskewing, binarization, and noise reduction, to improve text recognition accuracy. Customization Options: Tesseract allows users to fine-tune OCR parameters and train custom models for specific use cases, enhancing accuracy and performance. 3.2 Code Example using Patagames.Ocr; class TesseractExample { static void Main(string[] args) { // Create an OCR API instance using (var api = OcrApi.Create()) { // Initialize the OCR engine for the English language api.Init(Patagames.Ocr.Enums.Languages.English); // Extract text from the image string plainText = api.GetTextFromImage(@"C:\Users\buttw\source\repos\ironqr\ironqr\bin\Debug\net5.0\Iron.png"); // Display the extracted text Console.WriteLine(plainText); } } } using Patagames.Ocr; class TesseractExample { static void Main(string[] args) { // Create an OCR API instance using (var api = OcrApi.Create()) { // Initialize the OCR engine for the English language api.Init(Patagames.Ocr.Enums.Languages.English); // Extract text from the image string plainText = api.GetTextFromImage(@"C:\Users\buttw\source\repos\ironqr\ironqr\bin\Debug\net5.0\Iron.png"); // Display the extracted text Console.WriteLine(plainText); } } } Imports Patagames.Ocr Friend Class TesseractExample Shared Sub Main(ByVal args() As String) ' Create an OCR API instance Using api = OcrApi.Create() ' Initialize the OCR engine for the English language api.Init(Patagames.Ocr.Enums.Languages.English) ' Extract text from the image Dim plainText As String = api.GetTextFromImage("C:\Users\buttw\source\repos\ironqr\ironqr\bin\Debug\net5.0\Iron.png") ' Display the extracted text Console.WriteLine(plainText) End Using End Sub End Class $vbLabelText $csharpLabel 3.2.1 Output 4. IronOCR IronOCR, a powerful OCR engine developed by Iron Software, distinguishes itself with its exceptional accuracy, ease of use, and versatile language support. It offers on-premises OCR functionality and supports over 125 languages, making it suitable for global applications. IronOCR leverages advanced machine learning algorithms and cloud vision technology to deliver precise text recognition results, even in challenging scenarios. 4.1 Key Features of IronOCR High Accuracy: IronOCR delivers industry-leading accuracy in text recognition, ensuring reliable results across diverse document types and languages. Versatile Language Support: It supports over 125 languages and provides comprehensive language packs for seamless multilingual text recognition. Simple Integration: IronOCR offers straightforward integration with .NET applications, with intuitive APIs and extensive documentation to streamline the development process with pre-processing and post-processing original images to extract texts. 4.2 Install IronOCR Before moving to the coding example let's see how to install IronOCR using the NuGet Package Manager. In Visual Studio go to Tools Menu and Select NuGet Package Manager. A new list will appear, here select the NuGet Package Manager for solutions. A new window will appear, go to the 'Browse' tab and click type 'IronOCR' in the search bar. A list of Packages will appear. Select the latest IronOCR package and click on install. 4.3 Code Example (C#) using IronOcr; class IronOCRExample { static void Main(string[] args) { // Create an IronTesseract instance var ocr = new IronTesseract(); // Set the language for OCR recognition ocr.Language = OcrLanguage.English; // Perform OCR on the specified image var result = ocr.Read(@"C:\Users\buttw\source\repos\ironqr\ironqr\bin\Debug\net5.0\Iron.png"); // Display the extracted text Console.WriteLine(result.Text); } } using IronOcr; class IronOCRExample { static void Main(string[] args) { // Create an IronTesseract instance var ocr = new IronTesseract(); // Set the language for OCR recognition ocr.Language = OcrLanguage.English; // Perform OCR on the specified image var result = ocr.Read(@"C:\Users\buttw\source\repos\ironqr\ironqr\bin\Debug\net5.0\Iron.png"); // Display the extracted text Console.WriteLine(result.Text); } } Imports IronOcr Friend Class IronOCRExample Shared Sub Main(ByVal args() As String) ' Create an IronTesseract instance Dim ocr = New IronTesseract() ' Set the language for OCR recognition ocr.Language = OcrLanguage.English ' Perform OCR on the specified image Dim result = ocr.Read("C:\Users\buttw\source\repos\ironqr\ironqr\bin\Debug\net5.0\Iron.png") ' Display the extracted text Console.WriteLine(result.Text) End Sub End Class $vbLabelText $csharpLabel 4.3.1 Output 5. Comparative Assessment 5.1 Accuracy and Performance Windows OCR Engine and Tesseract offer decent accuracy but may struggle with complex layouts. IronOCR: Excels in accuracy, delivering reliable results across diverse document types and languages, including noisy images. 5.2 Ease of Integration Windows OCR Engine: Seamlessly integrates with Windows applications but lacks customization options. Tesseract: Requires additional configuration and dependencies for integration but offers extensive customization options. IronOCR: Provides simple integration with .NET applications, with intuitive APIs and comprehensive documentation. 5.3 Language Support Windows OCR Engine supports a limited number of languages compared to Tesseract and IronOCR. Tesseract: Offers support for over 100 languages. IronOCR: Provides support for over 125 languages, making it suitable for global applications. 6. Conclusion In conclusion, while Windows OCR Engine and Tesseract are popular choices for text recognition, IronOCR emerges as the most accurate and versatile OCR engine. Its industry-leading accuracy, extensive language support, and simple integration make it a standout solution for businesses and developers seeking reliable OCR functionality. By leveraging IronOCR, organizations can streamline document processing workflows, enhance data extraction accuracy, and unlock valuable insights from scanned documents and images. IronOCR offers a free trial. To know more about IronOCR and its features visit here. Kannapat Udonpant 今すぐエンジニアリングチームとチャット ソフトウェアエンジニア ソフトウェアエンジニアになる前に、Kannapatは北海道大学で環境資源の博士号を修了しました。博士号を追求する間に、彼はバイオプロダクションエンジニアリング学科の一部である車両ロボティクスラボラトリーのメンバーになりました。2022年には、C#のスキルを活用してIron Softwareのエンジニアリングチームに参加し、IronPDFに注力しています。Kannapatは、IronPDFの多くのコードを執筆している開発者から直接学んでいるため、この仕事を大切にしています。同僚から学びながら、Iron Softwareでの働く社会的側面も楽しんでいます。コードやドキュメントを書いていない時は、KannapatはPS5でゲームをしたり、『The Last of Us』を再視聴したりしていることが多いです。 関連する記事 更新日 6月 22, 2025 Power Automate OCR(開発者向けチュートリアル) この光学文字認識技術は、ドキュメントのデジタル化、自動化されたPDFデータの抽出とエントリ、請求書処理、スキャンPDFの検索可能化に応用されます。 詳しく読む 更新日 6月 22, 2025 Easyocr対Tesseract (OCR機能の比較) EasyOCR、Tesseract OCR、Keras-OCR、IronOCRのような人気のOCRツールやライブラリは、現代のアプリケーションにこの機能を統合するためによく利用されています。 詳しく読む 更新日 6月 22, 2025 画像をテキストに変換する方法 現代のデジタル時代では、画像ベースのコンテンツを読みやすい編集可能で検索可能なテキストに変換することが重要です。 詳しく読む クラウドベースのOCR(OCR機能の比較)Azure OCR対Google OCR(OCR機能...
更新日 6月 22, 2025 Power Automate OCR(開発者向けチュートリアル) この光学文字認識技術は、ドキュメントのデジタル化、自動化されたPDFデータの抽出とエントリ、請求書処理、スキャンPDFの検索可能化に応用されます。 詳しく読む
更新日 6月 22, 2025 Easyocr対Tesseract (OCR機能の比較) EasyOCR、Tesseract OCR、Keras-OCR、IronOCRのような人気のOCRツールやライブラリは、現代のアプリケーションにこの機能を統合するためによく利用されています。 詳しく読む