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.net-corethumbnailsexifimagesharp

How do I extract a jpeg's EXIF thumbnail using ImageSharp?

I am trying to extract thumbnails from source jpegs and save them to the file system, using the C# ImageSharp library. I see there is some mention of it in the intellisense for the component: SixLabors.ImageSharp.Image.Metadata.ExifProfile.CreateThumbnail()

...but I can't seem to find any documentation for it or examples to call it correctly.

I did find this:

using SixLabors.ImageSharp;
using SixLabors.ImageSharp.PixelFormats;
using SixLabors.ImageSharp.Processing;  

//method code:
Image<TPixel> thumbnail = image.Metadata.ExifProfile.CreateThumbnail<TPixel>();

https://docs.sixlabors.com/api/ImageSharp/SixLabors.ImageSharp.Metadata.Profiles.Exif.ExifProfile.html

...but I need to find where the TPixel type is to get it to work. VisualStudio doesn't recognize it and I can't seem to find a namespace or use it correctly:

"The type or namespace name 'TPixel' could not be found (are you missing a using directive or an assembly reference?)"

Legacy Windows .NET Framework could do this for System.Drawing.Image.Image.GetThumbnailImage() and it worked pretty well.

EDIT: Using tocsoft's answer, I changed the code to:

if (image.Metadata.ExifProfile != null)
{
    Image<Rgba32> thumbnail = image.Metadata.ExifProfile.CreateThumbnail<Rgba32>();

    thumbnail.Save(thumbnailPath, encoder);
}

...however, the image.Metadata.ExifProfile is null, which is unexpected since I know these source images have EXIF data.

EDIT: Actually, it's working now. Success! Thank you!

Solution

  • TPixel would be any of the pixel formats in the SixLabors.ImageSharp.PixelFormats namespace. But unless you are planning on interoperating with other systems that require the pixel data layed out in memory in specific ways you will likely just want to use Rgba32

    Image<Rgba32> thumbnail = image.Metadata.ExifProfile.CreateThumbnail<Rgba32>();