Dim document As PdfSharp.Pdf.PdfDocument = PdfSharp.Pdf.IO.PdfReader.Open(tpath)

        Dim imageCount As Integer = 0
        ' Iterate pages
        For Each page As PdfSharp.Pdf.PdfPage In document.Pages
  Dim resources As PdfSharp.Pdf.PdfDictionary = page.Elements.GetDictionary("/Resources")
            If resources IsNot Nothing Then
                ' Get external objects dictionary
                Dim xObjects As PdfSharp.Pdf.PdfDictionary = resources.Elements.GetDictionary("/XObject")
                If xObjects IsNot Nothing Then
                    Dim items As ICollection(Of PdfSharp.Pdf.PdfItem) = xObjects.Elements.Values
                    ' Iterate references to external objects
                    For Each item As PdfSharp.Pdf.PdfItem In items
                        Dim reference As PdfSharp.Pdf.Advanced.PdfReference = TryCast(item, PdfSharp.Pdf.Advanced.PdfReference)
                        If reference IsNot Nothing Then
                            Dim xObject As PdfSharp.Pdf.PdfDictionary = TryCast(reference.Value, PdfSharp.Pdf.PdfDictionary)
                            ' Is external object an image?
                            If xObject IsNot Nothing AndAlso xObject.Elements.GetString("/Subtype") = "/Image" Then
                                ExportImage(xObject, imageCount)
                            End If
                        End If
                    Next
                End If
            End If
        Next