Estoy buscando simplemente extraer todas las imágenes de un pdf. Encontré un código que parece que es exactamente lo que necesito

Private Sub getAllImages(ByVal dict As pdf.PdfDictionary, ByVal images As List(Of Byte()), ByVal doc As pdf.PdfReader)
Dim res As pdf.PdfDictionary = CType(pdf.PdfReader.GetPdfObject(dict.Get(pdf.PdfName.RESOURCES)), pdf.PdfDictionary)
Dim xobj As pdf.PdfDictionary = CType(pdf.PdfReader.GetPdfObject(res.Get(pdf.PdfName.XOBJECT)), pdf.PdfDictionary)

If xobj IsNot Nothing Then
    For Each name As pdf.PdfName In xobj.Keys
        Dim obj As pdf.PdfObject = xobj.Get(name)
        If (obj.IsIndirect) Then
            Dim tg As pdf.PdfDictionary = CType(pdf.PdfReader.GetPdfObject(obj), pdf.PdfDictionary)
            Dim subtype As pdf.PdfName = CType(pdf.PdfReader.GetPdfObject(tg.Get(pdf.PdfName.SUBTYPE)), pdf.PdfName)
            If pdf.PdfName.IMAGE.Equals(subtype) Then
                Dim xrefIdx As Integer = CType(obj, pdf.PRIndirectReference).Number
                Dim pdfObj As pdf.PdfObject = doc.GetPdfObject(xrefIdx)
                Dim str As pdf.PdfStream = CType(pdfObj, pdf.PdfStream)
                Dim bytes As Byte() = pdf.PdfReader.GetStreamBytesRaw(CType(str, pdf.PRStream))

                Dim filter As String = tg.Get(pdf.PdfName.FILTER).ToString
                Dim width As String = tg.Get(pdf.PdfName.WIDTH).ToString
                Dim height As String = tg.Get(pdf.PdfName.HEIGHT).ToString
                Dim bpp As String = tg.Get(pdf.PdfName.BITSPERCOMPONENT).ToString

                If filter = "/FlateDecode" Then
                    bytes = pdf.PdfReader.FlateDecode(bytes, True)
                    Dim pixelFormat As System.Drawing.Imaging.PixelFormat
                    Select Case Integer.Parse(bpp)
                        Case 1
                            pixelFormat = Drawing.Imaging.PixelFormat.Format1bppIndexed
                        Case 24
                            pixelFormat = Drawing.Imaging.PixelFormat.Format24bppRgb
                        Case Else
                            Throw New Exception("Unknown pixel format " + bpp)
                    End Select
                    Dim bmp As New System.Drawing.Bitmap(Int32.Parse(width), Int32.Parse(height), pixelFormat)
                    Dim bmd As System.Drawing.Imaging.BitmapData = bmp.LockBits(New System.Drawing.Rectangle(0, 0, Int32.Parse(width), Int32.Parse(height)), System.Drawing.Imaging.ImageLockMode.WriteOnly, pixelFormat)
                    Marshal.Copy(bytes, 0, bmd.Scan0, bytes.Length)
                    bmp.UnlockBits(bmd)
                    Using ms As New MemoryStream
                        bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Png)
                        bytes = ms.GetBuffer
                    End Using
                End If
                images.Add(bytes)
            ElseIf pdf.PdfName.FORM.Equals(subtype) Or pdf.PdfName.GROUP.Equals(subtype) Then
                getAllImages(tg, images, doc)
            End If
        End If
    Next
End If End Sub

Ahora mi problema es simplemente, ¿cómo puedo llamar a esto, no sé a qué configurar la variable dict o la lista de imágenes?

Así que si tengo un PDF ubicado en C: \ temp \ test.pdf que contiene imágenes, ¿cómo llamo a esto?

    Dim x As New FileStream("C:\image\test.pdf", FileMode.Open)
    Dim reader As New iTextSharp.text.pdf.PdfReader(x)
    getAllImages(?????, ?????? ,reader)