private void CreateImagePart(PackagePart sourcePart, BitmapSource imageSource, string imageContentType, int imageIndex) { string imageName = WpfPayload.GetImageName(imageIndex, imageContentType); Uri uri = new Uri("/Xaml" + imageName, UriKind.Relative); PackagePart packagePart = this._package.CreatePart(uri, imageContentType, CompressionOption.NotCompressed); PackageRelationship packageRelationship = sourcePart.CreateRelationship(uri, TargetMode.Internal, "http://schemas.microsoft.com/wpf/2005/10/xaml/component"); BitmapEncoder bitmapEncoder = WpfPayload.GetBitmapEncoder(imageContentType); bitmapEncoder.Frames.Add(BitmapFrame.Create(imageSource)); Stream stream = packagePart.GetStream(); using (stream) { bitmapEncoder.Save(stream); } }