C#: Converting byte[] to UTF8 encoded string

Question

I am using a library called EXIFextractor to extract metadata information from images. This lib in part is using System.Drawing.Imaging.PropertyItem to do all the hard work. Some of the data in PropertyItem, such as Image Details etcetera, are fetched as an ASCII-string stored in a byte[] according to the Microsoft documentation.

My problem is that international characters (å, ä, ö, etcetera) are dropped and replaced by questionmarks. When I debug the code it is apparent that the byte[] is a representation of an UTF-8.

I'd like to parse the byte[] as an UTF8-string, how can I do this without loosing any information in the process?

Thanks in advance!

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Update:

I have been asked to provide a snippet from my code:

The first snippet is from the class I use, namely the EXIFextractor.cs written by Asim Goheer

foreach( System.Drawing.Imaging.PropertyItem p in parr )
{
 string v = ""; 

                // ...

 else if( p.Type == 0x2 )
 {
  // string     
  v = ascii.GetString(p.Value);
 }

And this is my code where I try my best to handle the results of the above.

                try {
  EXIFextractor exif = new EXIFextractor(ref bmp, "");
  object o;
                    if ((o = exif["Image Description"]) != null)
                        MediaFile.Description = Tools.UTF8Encode(o.ToString()); 

I have also tried a couple of other ways of getting my precious å, ä, ö from the data, but nothing seems to do the trick. I am starting to think Hans Passant is right about his conclusions in his answer below.

Answer 1

Use the GetString method on the Encoding.UTF8 object.

Answer 2

string yourText = Encoding.UTF8.GetString(yourByteArray);

Answer 3

Maybe you could try another encoding? UTF16, Unicode? If you aren't sure if it got encodes right in the first place try to view the exif metadata with another exif reader.

Answer 4

Yes, this is a problem with the app or camera that originated the image. The EXIF standard has horrible support for text, it has to be encoded in ASCII. That only ever works out well when the photographer speaks English. No doubt the software that encoded the image is ignoring this requirement. Which is what the PropertyItem class is doing as well, it encodes a string to byte[] with Marshal.StringToHGlobalAnsi(), which assumes the system's default code page.

There's no obvious fix for this, you'll get mojibake when the photo was made too far away from your machine.