IRONOCRの使い方 C#でOCRを使用して身分証明書を読む方法 Kannapat Udonpant 更新日:6月 22, 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 Optical Character Recognition (OCR) technology has become an invaluable tool for automating the extraction of text from images, enabling efficient data retrieval and analysis and avoiding human error. This technology can be used to read driving licenses, passports, institution official documents, ID cards, residence permit cards, and travel documents of multiple languages and different countries to the exact expiration date, nationality, date of birth, etc. All the data extracted can be further fed to machine learning and artificial intelligence software products. In this article, we will explore how to leverage IronOCR, a powerful OCR library in C# from Iron Software, to read and extract information from identity documents. IronOCR provides a straightforward and flexible OCR solution in the form of APIs for OCR tasks, making it an excellent choice for developers looking to integrate OCR software capabilities into their applications. IronOCR enables computers to recognize and extract text from images, scan existing documents, or any other visual representation of text. To extract data, it involves a series of complex processes that mimic the way humans perceive and interpret text visually. This process involves Image Pre-processing, Text Detection, Character Segmentation, Feature Extraction, Character Recognition, and Post-Processing to correct errors. How to Read Identity Documents Using OCR in C# Create a new C# project in Visual Studio Install the IronOCR .NET library and add it to your project. Read Identity document images using the IronOCR library. Read the identity documents from PDFs. IronOCR, crafted and maintained by Iron Software, serves as a powerful library for C# Software Engineers, facilitating OCR, Barcode Scanning, and Text Extraction within .NET projects. Key Features of IronOCR Text Reading Versatility Capable of reading relevant data from various formats, including images (JPEG, PNG, GIFF, TIFF, BMP), Streams, and PDFs. Image Enhancement Corrects low-quality scans and photos through an array of filters such as Deskew, Denoise, Binarize, Enhance Resolution, Dilate, and more. Barcode Recognition Supports reading barcodes from a wide range of formats, encompassing over 20 barcode types, with added QR code recognition. Tesseract OCR Integration Utilizes the latest build of Tesseract OCR, finely tuned for optimal performance in extracting text from images. Flexible Output Options Allows the export of searchable PDFs, HTML, and text content from image files, offering flexibility in managing extracted information. Now, let's delve into the development of a demo application that utilizes IronOCR to read ID documents. Prerequisites Visual Studio: Ensure you have Visual Studio or any other C# development environment installed. NuGet Package Manager: Make sure you can use NuGet to manage packages in your project. Step 1: Create a New C# Project in Visual Studio Begin by creating a fresh C# console application in Visual Studio, or alternatively, utilize an existing project. Select "Add New Project" from the Menu, then select console application from the templates below. Provide a project name and location in the below windows. Select the required .NET Version. Click the Create button to create the new project. Step 2: Install the IronOCR library and add it to your project. IronOCR can be found in the NuGet package manager and can be installed using the package manager console with the following command: Install-Package IronOcr IronOCR can also be installed using Visual Studio. Open the NuGet Package manager, search for IronOCR like below, and click install. Once installed, the application is ready to make use of IronOCR to read any identity document for data extraction and identity verification, reducing manual data entry work. Step 3: Read Identity Document Images using the IronOCR library Using OCR for processing ID documents involves many steps, which are detailed below. Image Pre-processing The OCR ID document processing begins with acquiring an image containing text. This image could be scanned ID documents, a photograph of ID cards, or any other visual representation of text. Identity card pre-processing steps may include resizing, noise reduction, and enhancement to improve the quality and clarity of the image. Text Detection OCR algorithms need to locate the specific data areas within the image where text is present. This step involves identifying text regions or bounding boxes. Character Segmentation Once text regions or data fields are identified, the image is further analyzed to segment individual characters. This step is crucial for languages that use distinct characters, like English or Chinese. Feature Extraction OCR algorithms analyze the segmented characters to extract features that help in differentiating between different characters. These features might include stroke patterns, shape, and spatial relationships between elements. Character Recognition Based on the extracted features, OCR algorithms classify each segmented character and assign it a corresponding textual representation. Machine learning models, such as neural networks, are often employed in this step. Post-Processing The recognized characters may undergo post-processing to correct errors or enhance accuracy. This step may involve dictionary-based corrections, context analysis, or language modeling. IronOCR library takes care of all the above steps and allows us to perform OCR using just a few lines of code, saving time-consuming tedious tasks. using IronOcr; class Program { public static void Main() { // Configure IronTesseract with language and other settings var ocrTesseract = new IronTesseract() { Language = OcrLanguage.EnglishBest, Configuration = new TesseractConfiguration() { ReadBarCodes = false, // Disable reading of barcodes BlackListCharacters = "`ë|^", // Blacklist specific characters PageSegmentationMode = TesseractPageSegmentationMode.AutoOsd, // Set page segmentation mode } }; // Define the OCR input image using var ocrInput = new OcrInput("id1.png"); // Perform OCR on the input image var ocrResult = ocrTesseract.Read(ocrInput); // Display the extracted text Console.WriteLine(ocrResult.Text); } } using IronOcr; class Program { public static void Main() { // Configure IronTesseract with language and other settings var ocrTesseract = new IronTesseract() { Language = OcrLanguage.EnglishBest, Configuration = new TesseractConfiguration() { ReadBarCodes = false, // Disable reading of barcodes BlackListCharacters = "`ë|^", // Blacklist specific characters PageSegmentationMode = TesseractPageSegmentationMode.AutoOsd, // Set page segmentation mode } }; // Define the OCR input image using var ocrInput = new OcrInput("id1.png"); // Perform OCR on the input image var ocrResult = ocrTesseract.Read(ocrInput); // Display the extracted text Console.WriteLine(ocrResult.Text); } } Imports IronOcr Friend Class Program Public Shared Sub Main() ' Configure IronTesseract with language and other settings Dim ocrTesseract = New IronTesseract() With { .Language = OcrLanguage.EnglishBest, .Configuration = New TesseractConfiguration() With { .ReadBarCodes = False, .BlackListCharacters = "`ë|^", .PageSegmentationMode = TesseractPageSegmentationMode.AutoOsd } } ' Define the OCR input image Dim ocrInput As New OcrInput("id1.png") ' Perform OCR on the input image Dim ocrResult = ocrTesseract.Read(ocrInput) ' Display the extracted text Console.WriteLine(ocrResult.Text) End Sub End Class $vbLabelText $csharpLabel Input Image Below is a sample image used as input for the program. Output Code Explanation The above code uses the IronOCR library to read all the text fields from the ID document. We use the IronTesseract class from the IronOCR library and configure it to use the English language and some blacklisted characters. Then we declare the OCR input using the OcrInput class and read the text from the image. The extracted text fields can be seen in the console output. Step 4: Read Identity documents from PDFs. We can also read from PDF documents. For this, we can use the IronPDF library from IronSoftware. First, install the library like below: Install-Package IronOcr using IronOcr; using IronPdf; class Program { public static void Main() { // Load the PDF document var pdfReader = new PdfDocument("id1.pdf"); // Initialize IronTesseract for OCR var ocrTesseract = new IronTesseract(); // Create OCR input from the PDF stream using var ocrInput = new OcrInput(); ocrInput.AddPdf(pdfReader.Stream); // Perform OCR on the PDF input var ocrResult = ocrTesseract.Read(ocrInput); // Display the extracted text Console.WriteLine(ocrResult.Text); } } using IronOcr; using IronPdf; class Program { public static void Main() { // Load the PDF document var pdfReader = new PdfDocument("id1.pdf"); // Initialize IronTesseract for OCR var ocrTesseract = new IronTesseract(); // Create OCR input from the PDF stream using var ocrInput = new OcrInput(); ocrInput.AddPdf(pdfReader.Stream); // Perform OCR on the PDF input var ocrResult = ocrTesseract.Read(ocrInput); // Display the extracted text Console.WriteLine(ocrResult.Text); } } Imports IronOcr Imports IronPdf Friend Class Program Public Shared Sub Main() ' Load the PDF document Dim pdfReader = New PdfDocument("id1.pdf") ' Initialize IronTesseract for OCR Dim ocrTesseract = New IronTesseract() ' Create OCR input from the PDF stream Dim ocrInput As New OcrInput() ocrInput.AddPdf(pdfReader.Stream) ' Perform OCR on the PDF input Dim ocrResult = ocrTesseract.Read(ocrInput) ' Display the extracted text Console.WriteLine(ocrResult.Text) End Sub End Class $vbLabelText $csharpLabel The above code uses IronPDF to load the id1.pdf document, and the PDF is passed as a stream to OcrInput and ocrTesseract. Output Licensing (Free Trial Available) To use IronOCR, you'll need a license key. This key needs to be placed in appsettings.json. { "IRONOCR-LICENSE-KEY": "your license key" } Provide a user email ID to get a trial license. Use cases 1. Identity Verification in Financial Services: Use Case: Banks and financial institutions utilize OCR to read identity documents such as passports, driver's licenses, and ID cards during the customer onboarding and KYC process. Benefits: Ensures accurate and efficient identity verification for account creation, loan applications, and other financial transactions. 2. Border Control and Immigration: Use Case: Immigration authorities employ OCR technology to read and authenticate information from passports and visas at border checkpoints. Benefits: Streamlines the immigration process, enhances security, and reduces manual data entry errors. 3. Access Control and Security: Use Case: OCR is used in access control systems to read information from ID cards, employee badges, or facial recognition scans for secure entry into buildings or restricted areas. Benefits: Enhances security by ensuring only authorized individuals gain access and provides a digital record of entries. 4. E-Government Services: Use Case: Government agencies use OCR to process and verify ID documents submitted online for services such as driver's license renewals, tax filings, and permit applications. Benefits: Improves efficiency, reduces paperwork, and enhances the overall citizen experience. 5. Healthcare Identity Verification: Use Case: Healthcare providers use OCR to read information from patient IDs, insurance cards, and other identity documents for accurate patient record-keeping. Benefits: Facilitates precise patient identification, ensures proper medical record management, and supports billing processes. 6. Automated Hotel Check-In: Use Case: Hotels implement OCR for automated check-in processes by scanning guests' identity documents, streamlining the registration process. Benefits: Enhances guest experience, reduces check-in time, and minimizes errors in capturing guest information. 7. Smart Cities and Public Services: Use Case: OCR is applied in smart city initiatives to read identity documents for services like public transportation access, library memberships, and city event registrations. Benefits: Improves the efficiency of public services, facilitates seamless access, and enhances urban living experiences. 8. Education Administration: Use Case: Educational institutions use OCR to process and verify ID documents during student admissions, examinations, and issuance of academic credentials. Benefits: Ensures accurate student records, reduces administrative burden, and enhances the integrity of academic processes. Conclusion Integrating OCR technology into your C# application using IronOCR allows you to efficiently extract information from ID documents. This comprehensive guide provides the necessary steps to set up your project and use IronOCR to read and process identity document images. Experiment with the code examples to tailor the extraction process to your specific requirements, providing a seamless and automated solution for handling identity document data. よくある質問 C#を使って身分証明書からテキストを抽出するにはどうすればよいですか? IronSoftwareの専門的なOCRライブラリであるIronOCRを使用することで、パスポート、IDカード、運転免許証などのさまざまな身分証明書からテキストを抽出できます。IronOCRはVisual StudioのNuGetパッケージマネージャーを通じてインストールでき、画像とPDFからテキストを読み取るためのメソッドを使用できます。 身分証明書にOCRを使用する利点は何ですか? IronSoftwareのIronOCRのようなOCR技術は、身分証明書からのテキスト抽出を自動化し、人為的エラーを減少させ、データ取得の効率を向上させます。複数の言語とドキュメント形式をサポートしており、金融、医療、国境管理などの分野での応用に最適です。 C#プロジェクトでOCRを設定するための手順は何ですか? C#プロジェクトでOCRを設定するには、Visual Studioで新しいプロジェクトを作成し、NuGetパッケージマネージャーを通じてIronOCRをインストールし、そのAPIを利用して文書からテキストを読み取る必要があります。IronOCRはOCR機能の統合を助けるために、包括的なドキュメントと例を提供しています。 OCRの結果を向上させるために画像品質を向上させる方法はありますか? IronOCRには、スキュー除去、デノイズ、二値化、解像度の向上、拡張などの画像品質を向上させる機能があります。これらのフィルターは、低品質の画像からのテキスト認識の精度を向上させ、信頼できるデータ抽出を保証します。 OCR技術は身分証明書からバーコードを読み取ることができますか? はい、IronOCRは身分証明書からのバーコード認識をサポートしています。QRコードを含む20種類以上のバーコードを読み取ることができ、テキストとバーコードデータの抽出を必要とするアプリケーションに役立ちます。 身分証明における特定の使用例はありますか? OCRは、自動チェックイン、アクセスコントロール、電子政府サービスなどのアプリケーションでの身分証明によく使用されています。IronOCRは、身分証明書からテキストを抽出し検証するために必要なツールを提供し、セキュリティを強化しプロセスを合理化します。 OCRで多言語テキスト抽出をどのように処理できますか? IronOCRは多言語サポートを提供しており、さまざまな言語の文書からテキストを抽出することができます。この機能は、異なる言語の文書が効率的に処理される必要がある国際的なアプリケーションで特に有用です。 OCRライブラリの試用版はありますか? IronSoftwareのIronOCRは無料の試用版を提供しています。メールアドレスを提供することで試用版のライセンスキーを入手でき、購入前にライブラリの機能を探ることができます。 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 公開日 9月 29, 2025 IronOCRを使用して.NET OCR SDKを作成する方法 IronOCRの.NET SDKで強力なOCRソリューションを構築。シンプルなAPI、エンタープライズ機能、クロスプラットフォーム対応。 詳しく読む 公開日 9月 29, 2025 IronOCRを使用してC# GitHubプロジェクトにOCRを統合する方法 OCR C# GitHubチュートリアル:IronOCRを使用してGitHubプロジェクトにテキスト認識を実装。コードサンプルとバージョン管理のヒントを含む。 詳しく読む 更新日 9月 4, 2025 私たちが文書処理メモリを98%削減した方法:IronOCRのエンジニアリングブレークスルー IronOCR 2025.9は、TIFF処理メモリを98%削減するストリーミングアーキテクチャを採用し、クラッシュを回避し、企業のワークフローのために速度を向上。 詳しく読む C#でOCRを使用した文字認識の作成方法C#でOCRレシートスキャナー...
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