Scan and convert files to TIFF in C#

This guide explains how to scan a physical document with a scanner and then save the scanned image as a TIFF file. This guide uses the TWAIN protocol(opens in a new tab).

Printing and scanning aren’t supported in the cross-platform .NET 6.0 assembly. For more information, see the system compatibility guide.

To get an image from a scanner and then save it as a TIFF file, follow these steps:

  1. Create a GdPictureImaging object.
  2. Store the handle of the active windows in a variable by calling the IntPtr.Zero structure.
  3. Select the scanner by passing the handle to the TwainSelectSource and the TwainOpenDefaultSource methods of the GdPictureImaging object.
  4. Optional: Hide the scanning user interface with the TwainSetHideUI method of the GdPictureImaging object. Use this setting when your application cannot communicate with the scanner.
  5. Get the image from the scanner by passing the handle to the TwainAcquireToGdPictureImage method of the GdPictureImaging object.
  6. Save the scanned image with the SaveAsTIFF method of the GdPictureImaging object. This method takes the following parameters:
    • The image ID.
    • The file path of the output file.
    • The TIFF compression method. This parameter is a member of the TiffCompression enumeration.
  7. Release unnecessary resources and close the TWAIN source handle.

The example below gets an image from a scanner and then saves it as a TIFF file:

using GdPictureImaging gdpictureImaging = new GdPictureImaging();
// Store the handle of the active windows in a variable.
IntPtr WINDOW_HANDLE = IntPtr.Zero;
// Select the scanner.
gdpictureImaging.TwainSelectSource(WINDOW_HANDLE);
gdpictureImaging.TwainOpenDefaultSource(WINDOW_HANDLE);
// (Optional) Hide the scanning user interface.
gdpictureImaging.TwainSetHideUI(true);
// Get the image from the scanner.
int imageId = gdpictureImaging.TwainAcquireToGdPictureImage(WINDOW_HANDLE);
// Save the scanned image.
gdpictureImaging.SaveAsTIFF(imageId, @"C:\temp\output.tiff", TiffCompression.TiffCompressionAUTO);
// Release unnecessary resources.
gdpictureImaging.ReleaseGdPictureImage(imageId);
gdpictureImaging.TwainCloseSource();

Used methods

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