Image Text Finder
How to Create an Image Text Search Web App with Aspose.OCR

How to Create an Image Text Search Web App with Aspose.OCR

Adding OCR-powered text search to web apps can streamline compliance, e-discovery, and digital asset management. With Aspose.OCR Image Text Finder for .NET and ASP.NET Core, you can create a user-friendly interface for interactive searching and highlighting in uploaded images.

Real-World Problem

Users need to instantly search for keywords or patterns inside images—without downloading or manually reviewing every scan. Interactive apps save time and reduce risk of missed data.

Solution Overview

Build a web UI to upload images, run keyword searches using OCR, and return/expose results with real-time highlighting.

Prerequisites

  1. Visual Studio 2019 or later
  2. .NET 6.0 or later (ASP.NET Core)
  3. Aspose.OCR for .NET from NuGet
  4. Basic Razor Pages or MVC experience
PM> Install-Package Aspose.OCR
PM> dotnet add package Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation

Step-by-Step Implementation

Step 1: Set Up the ASP.NET Core Web Project 

dotnet new webapp -n ImageTextFinderWeb
cd ImageTextFinderWeb

Step 2: Add Upload and Search UI (Razor Example)

Add to Pages/Index.cshtml:

<form enctype="multipart/form-data" method="post">
    <input type="file" name="imageFile" />
    <input type="text" name="searchTerm" placeholder="Enter keyword or pattern" />
    <button type="submit">Search</button>
</form>
@if (Model.ResultText != null)
{
    <h3>Extracted Text:</h3>
    <pre>@Model.ResultText</pre>
    <h4>Found: @Model.KeywordFound</h4>
}

Step 3: Handle Upload, OCR, and Search Logic

Add to Pages/Index.cshtml.cs:

using Aspose.OCR;
public string ResultText { get; set; }
public bool KeywordFound { get; set; }
public async Task OnPostAsync(IFormFile imageFile, string searchTerm)
{
    if (imageFile != null && !string.IsNullOrWhiteSpace(searchTerm))
    {
        var filePath = Path.GetTempFileName();
        using (var stream = System.IO.File.Create(filePath))
            await imageFile.CopyToAsync(stream);
        RecognitionSettings settings = new RecognitionSettings();
        settings.Language = Language.English;
        AsposeOcr ocr = new AsposeOcr();
        var result = ocr.Recognize(new OcrInput(InputType.SingleImage) { filePath }, settings)[0];
        ResultText = result.RecognitionText;
        KeywordFound = ocr.ImageHasText(filePath, searchTerm, settings);
        // Optional: highlight logic for UI
    }
}

Step 4: Highlight Results in UI (Optional)

Use basic string replacement or JavaScript to visually highlight found keywords in ResultText.

Step 5: Error Handling and Security

  • Validate file types and limit upload size
  • Use try/catch for robust operation

Use Cases and Applications

Compliance & e-Discovery

Instantly search for confidential terms inside uploads during review.

Digital Asset Management

Empower users to tag, review, or classify image assets on upload.

Customer Service

Let support teams check for PII or special clauses without downloading full documents.

Common Challenges and Solutions

Challenge 1: Performance with Large Images

Solution: Limit upload size, optimize OCR config, queue long-running jobs.

Challenge 2: Security and Input Validation

Solution: Validate file types and sanitize text results.

Challenge 3: Highlighting Complex Patterns

Solution: Use regex or JavaScript for robust match/highlight.

Performance Considerations

  • Offload large jobs to background processing
  • Use async file IO and OCR for responsiveness
  • Monitor server resource use

Best Practices

  1. Always validate uploads
  2. Limit file sizes and restrict types
  3. Log user searches for audit trail
  4. Deploy over HTTPS for security

Advanced Scenarios

Scenario 1: Batch Uploads and Multi-Image Search

Let users upload several images, search across all, and view batch results.

Scenario 2: Save/Export Search Results

Offer downloadable CSV or highlighted PDF outputs from the UI.

Conclusion

With Aspose.OCR Image Text Finder and ASP.NET Core, you can deliver user-friendly, interactive image text search for compliance, digital asset management, or customer-facing tools.

See Aspose.OCR for .NET API Reference for additional integration examples.

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