HeifDecoder Class

public class HeifDecoder : MultiFramedImageDecoder

Public Class HeifDecoder
	Inherits MultiFramedImageDecoder

var imagesCount = heifDecoder.GetFrameCount(stream);
for (int i = 0; i < imagesCount; i++)
{
    using (var atalaImage = heifDecoder.Read(stream, i, null))
    {
        // .. process image here
    }
}

RegisteredDecoders.Decoders.Add(heifDecoder);

using (var atalaImage = new AtalaImage(stream))
{
    // .. process image here
}

var heifDocument = heifDecoder.GetHeifDocument(stream, null);
foreach (var heifImage in heifDocument.HeifImages)
{
    // reading auxiliary images
    foreach (var auxiliaryImage in heifImage.AuxiliaryImages)
    {
        // process auxiliary image
    }

    // retrieve AtalaImage 
    var atalaImage = heifImage.GetImage();
}

using (var document = heifDecoder.GetHeifDocument(stream, null))
{
    foreach (var heifImage in document.HeifImages)
    {
        foreach (var metadata in heifImage.Metadata)
        {
            if (metadata.Type.Equals("exif", StringComparison.CurrentCultureIgnoreCase))
            {
                var exifCollection = metadata.AsExifCollection();
                foreach (ExifTag exifTag in exifCollection)
                {
                    Console.WriteLine(exifTag.ToString());
                }
            } else if (metadata.Type.Equals("mime", StringComparison.CurrentCultureIgnoreCase) &&
                       metadata.ContentType.Equals("application/rdf+xml",
                           StringComparison.CurrentCultureIgnoreCase))
            {
                var doc = new XmlDocument();
                doc.LoadXml(System.Text.Encoding.UTF8.GetString(metadata.Data));

                StringWriter sw = new StringWriter();
                doc.Save(sw);

                Console.WriteLine(sw.ToString());
            }
        }
    }
}