How to Add 'Comments' to a JPEG File Using C#

Question

Within the property window of a JPEG image, there is a tab called 'Summary'. Within this tab, there is a field called 'Comments' I would like to write some c# code which will add a given string to this field e.g "This is a photo".

Does some kind soul out there know how to do this?

Many thanks.

Answer 1

Based on other answers I wrote the following class which allows various metadata manipulations. You use it like this:

var jpeg = new JpegMetadataAdapter(pathToJpeg);
jpeg.Metadata.Comment = "Some comments";
jpeg.Metadata.Title = "A title";
jpeg.Save();              // Saves the jpeg in-place
jpeg.SaveAs(someNewPath);  // Saves with a new path

The differences between my solution and the others are not large. Principally I have refactored this to be cleaner. I also use the higher level properties of BitmapMetadata, rather than the SetQuery method.

Here is the full code, which is licensed under the MIT licence. You will need to add references to PresentationCore, WindowsBase, and System.Xaml.

public class JpegMetadataAdapter
{
    private readonly string path;
    private BitmapFrame frame;
    public readonly BitmapMetadata Metadata;

    public JpegMetadataAdapter(string path)
    {
        this.path = path;            
        frame = getBitmapFrame(path);
        Metadata = (BitmapMetadata)frame.Metadata.Clone();
    }

    public void Save()
    {
        SaveAs(path);
    }

    public void SaveAs(string path)
    {
        JpegBitmapEncoder encoder = new JpegBitmapEncoder();
        encoder.Frames.Add(BitmapFrame.Create(frame, frame.Thumbnail, Metadata, frame.ColorContexts));
        using (Stream stream = File.Open(path, FileMode.Create, FileAccess.ReadWrite))
        {
            encoder.Save(stream);
        }
    }

    private BitmapFrame getBitmapFrame(string path)
    {
        BitmapDecoder decoder = null;
        using (Stream stream = File.Open(path, FileMode.Open, FileAccess.ReadWrite, FileShare.None))
        {
            decoder = new JpegBitmapDecoder(stream, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.OnLoad);
        }
        return decoder.Frames[0];
    }
}