Chinese characters encoding in picture EXIF tag?

Question

I have a program that writes to picture's EXIF tags, and everything works fine until I encounter some Chinese characters. Depending on the tag, it either works perfectly or doesn't.

using (var file = Image.FromFile(tempPath)){
            // Works fine with Chinese characters
            var propTitle = file.PropertyItems[0];
            propTitle.Id = 0x010E;
            propTitle.Type = 2;
            propTitle.Value = Encoding.UTF8.GetBytes($"{title}\0");
            propTitle.Len = propTitle.Value.Length;
            file.SetPropertyItem(propTitle);

            // Doesn't work
            var propTags = file.PropertyItems[0];
            propTags.Id = 0x9286;
            propTags.Type = 2;
            propTags.Value = Encoding.UTF8.GetBytes($"{tags}\0");
            propTags.Len = propTags.Value.Length;
            file.SetPropertyItem(propTags);

            file.Save(finalPath);}

When I go and check the tags in Windows, the last tag (which is for user comments) shows up as:

高雄;城市;高楼大厦;中国å°æ¹¾;夜晚的景观;

While the other tags, such as the title, show up fine:

夜晚

But if I save that same string to another tag, it will show up fine in Windows Explorer:

高雄;城市;高楼大厦;中国台湾;夜晚的景观;

I thought at one point that the user comment tag didn't handle Chinese characters properly, but I can manually add them to the file and it works fine.

What am I doing wrong?

Answer 1

I know it's an old question, but i had the same problem with polish characters. In my case these user comment settings worked (type: 1, id: 40092, encoding: Unicode).

        byte[] val = System.Text.Encoding.Unicode.GetBytes($"źąćę\0");
        PropertyItem propItem = (PropertyItem)FormatterServices.GetUninitializedObject(typeof(PropertyItem));
        propItem.Id = 40092;
        propItem.Type = 1;
        propItem.Len = val.Length;
        propItem.Value = val;