Getting any image from filesystem in UWP app

Question

I am writing an app that parses MD (Markdown) files, but I cannot seem to get images to work properly. Let's say that the file specifies a relative image:

![My image](../image.jpg)

I am telling UWP to use the following URI for the file: file:////, which results in file:///c:/somewhere/data/../image.jpg. But nothing shows up, and I do not get an exception or anything indicating that I do not have access to the file system, though I am suspecting that I do not.

Is there anything I can do to get images to load in this way?

This is how I intend to use the image:

                else if (line.StartsWith("!"))
                {
                    var s = line.IndexOf("(") + 1;
                    var n = line.IndexOf(")") - s;
                    var imagePath = line.Substring(s, n);

                    Uri uri;

                    if (!imagePath.Contains(Uri.UriSchemeHttp) && !imagePath.ToString().Contains(Uri.UriSchemeHttps))
                    {
                        // Local image, relative to the document.
                        uri = new Uri(this.fileUri + imagePath);
                    }
                    else
                    {
                        uri = new Uri(imagePath);
                    }

                    var bitmap = new BitmapImage
                    {
                        UriSource = uri
                    };

                    parent.Children.Add(new Image()
                    {
                        Source = bitmap,
                        Stretch = Stretch.None,
                        HorizontalAlignment = HorizontalAlignment.Left
                    });
                }