Image Deskew
How to Batch Deskew Multiple Scanned Images Using .NET

How to Batch Deskew Multiple Scanned Images Using .NET

When you have dozens or hundreds of crooked scans, manual deskew is a bottleneck. Aspose.Imaging for .NET makes batch deskewing fast and easy—ideal for document management, archival, and business automation.

Real-World Problem

Large volumes of scanned documents/photos are rarely aligned perfectly, causing issues for OCR, compliance, or presentation. Manual correction is not scalable.

Solution Overview

Automate deskew for an entire folder of images in a single script. Customize settings, background color, and output format for your workflow.

Prerequisites

  1. Visual Studio 2019 or later
  2. .NET 6.0 or later (or .NET Framework 4.6.2+)
  3. Aspose.Imaging for .NET from NuGet
  4. Folders for input scans and output results
PM> Install-Package Aspose.Imaging

Step-by-Step Implementation

Step 1: Set Up Input/Output Folders 

string inputDir = "./input_scans";
string outputDir = "./deskewed_scans";
Directory.CreateDirectory(outputDir);

Step 2: Loop Over and Deskew Each Image 

using Aspose.Imaging;
using Aspose.Imaging.ImageOptions;

string[] files = Directory.GetFiles(inputDir, "*.jpg"); // Or *.png, *.tif, etc.
foreach (var file in files)
{
    try
    {
        using (var image = (RasterImage)Image.Load(file))
        {
            image.NormalizeAngle(false, Color.White); // Keep original size, fill background with white
            string outPath = Path.Combine(outputDir, Path.GetFileName(file));
            image.Save(outPath, new JpegOptions { Quality = 90 });
        }
    }
    catch (Exception ex)
    {
        // Log or report the error for review
        Console.WriteLine($"Failed to deskew {file}: {ex.Message}");
    }
}

Step 3: Review and Quality Control

After processing, preview deskewed files and handle any exceptions or files that didn’t process.

Use Cases and Applications

  • Digitizing archives for libraries or compliance
  • Batch-fixing receipts, forms, or multi-page documents
  • Preparing large volumes of scans for OCR or export

Common Challenges and Solutions

Some files fail or are unsupported: Log and skip, or check input types.

Quality varies on old/faded scans: Experiment with background color or pre-process images for better results.

Folder contains mixed formats: Use multiple search patterns or validate in code.

Best Practices

  • Use robust error handling in batch jobs
  • Preview results before archiving or sharing
  • Automate as part of a regular scan workflow

FAQ

Q: Can I run this on TIFF, PNG, or BMP images? A: Yes—Aspose.Imaging supports most raster formats. Adjust the search pattern as needed.

Q: Can I set background color for transparent output? A: Use Color.Transparent for graphics, or match your documents’ background.

Q: Is there a speed benefit to parallel processing? A: Yes, but manage memory usage and image disposal carefully in parallel jobs.

Conclusion

Batch deskewing with Aspose.Imaging for .NET saves hours and ensures consistent, professional results across large scan sets. For more batch features and troubleshooting, visit the Aspose.Imaging for .NET API Reference .

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