Allow me to answer my own question. :)

I did manage to get the xml in the file using a hack, and then I had access
to the xml-metadata.

It is certainly NOT very pretty code, but it will give another developer
facing a similar challenge something to work with. :)

Public Class ImageMetaData

Public CaptionWriter As String

Public AuthorsPosition As String

Public Credit As String

Public Source As String

Public Category As String

Public Colormode As String

Public ICCProfile As String

Public DateCreated As String

Public Urgency As String

Public Instructions As String

Public Headline As String

Public Description As String

Public Sub New(ByVal filename As String)

Dim xmpXmlDoc As String

xmpXmlDoc = GetXmpXmlDocFromImage(filename)

LoadDoc(xmpXmlDoc)

End Sub

Private Sub LoadDoc(ByVal xmpXmlDoc As String)

Dim xr As New Xml.XmlDocument

Dim nl As Xml.XmlNodeList

Try

xr.LoadXml(xmpXmlDoc)

Catch ex As Exception

Throw New ApplicationException("An error occured while loading XML metadata
from image. The error was: " & ex.Message)

End Try

Try

xr.LoadXml(xmpXmlDoc)

nl = xr.GetElementsByTagName("dc:description")

Me.Description = nl.Item(0).ChildNodes(0).InnerText()

nl = xr.GetElementsByTagName("photoshop:CaptionWriter")

Me.CaptionWriter = nl.Item(0).InnerText()

nl = xr.GetElementsByTagName("photoshop:AuthorsPosition")

Me.AuthorsPosition = nl.Item(0).InnerText()

nl = xr.GetElementsByTagName("photoshop:Credit")

Me.Credit = nl.Item(0).InnerText()

nl = xr.GetElementsByTagName("photoshop:Source")

Me.Source = nl.Item(0).InnerText()

nl = xr.GetElementsByTagName("photoshop:Category")

Me.Category = nl.Item(0).InnerText()

nl = xr.GetElementsByTagName("photoshop:ColorMode")

Me.Colormode = nl.Item(0).InnerText()

nl = xr.GetElementsByTagName("photoshop:ICCProfile")

Me.ICCProfile = nl.Item(0).InnerText()

nl = xr.GetElementsByTagName("photoshop:DateCreated")

Me.DateCreated = nl.Item(0).InnerText()

nl = xr.GetElementsByTagName("photoshop:Urgency")

Me.Urgency = nl.Item(0).InnerText()

nl = xr.GetElementsByTagName("photoshop:Instructions")

Me.Instructions = nl.Item(0).InnerText()

nl = xr.GetElementsByTagName("photoshop:Headline")

Me.Headline = nl.Item(0).InnerText()

Catch ex As Exception

Throw New ApplicationException("Error occured while readning meta-data from
image. The error was: " & ex.Message)

Finally

nl = Nothing

xr = Nothing

End Try

End Sub

Public Overrides Function Tostring() As String

Dim output

output += "CaptionWriter: " & Me.CaptionWriter & vbCrLf

output += "AuthorsPosition: " & Me.AuthorsPosition & vbCrLf

output += "Credit: " & Me.Credit & vbCrLf

output += "Source: " & Me.Source & vbCrLf

output += "Category: " & Me.Category & vbCrLf

output += "Colormode: " & Me.Colormode & vbCrLf

output += "ICCProfile: " & Me.ICCProfile & vbCrLf

output += "DateCreated: " & Me.DateCreated & vbCrLf

output += "Urgency: " & Me.Urgency & vbCrLf

output += "Instructions: " & Me.Instructions & vbCrLf

output += "Headline: " & Me.Headline & vbCrLf

output += "Description: " & Me.Description & vbCrLf

Return output

End Function

Public Shared Function GetXmpXmlDocFromImage(ByVal filename As String) As
String

Dim contents As String

Dim xmlPart As String

Dim beginCapture As String = "<x:xmpmeta"

Dim endCapture As String = "</x:xmpmeta>"

Dim beginPos, endPos As Integer

Dim sr As New System.IO.StreamReader(filename)

contents = sr.ReadToEnd

Debug.Write(contents.Length & " chars" & vbCrLf)

sr.Close()

sr = Nothing

beginPos = InStr(contents, beginCapture, CompareMethod.Text) - 1

endPos = InStr(contents, endCapture, CompareMethod.Text)

Debug.Write("xml found at pos: " & beginPos.ToString & " - " &
endPos.ToString)

xmlPart = contents.Substring(beginPos, (endPos - beginPos) +
endCapture.Length)

Debug.Write("Xml len: " & xmlPart.Length.ToString)

Return xmlPart

End Function

End Class