iTextSharp problemas em pegar string e imagem do PDF!

PdfReader reader = null;
        Document sourceDocument = null;        

        try
        {

            string sourcePdfPath = "C:\\Users\\Fabiote\\Downloads\\Apostila de POO com C#.pdf";
            // Intialize a new PdfReader instance with the contents of the source Pdf file:
            reader = new PdfReader(sourcePdfPath);

            // For simplicity, I am assuming all the pages share the same size
            // and rotation as the first page:
            sourceDocument = new Document(reader.GetPageSizeWithRotation(1));            

            sourceDocument.Open();

            string extractText = "";
            // Walk the specified range and add the page copies to the output file:
            for (int i = 1; i <= reader.NumberOfPages ; i++)
            {                                                
                 ITextExtractionStrategy its = new iTextSharp.text.pdf.parser.SimpleTextExtractionStrategy();
                 extractText += PdfTextExtractor.GetTextFromPage(reader, i, its);
                 //extractText = Encoding.UTF8.GetString(ASCIIEncoding.Convert(Encoding.Default, Encoding.UTF8, Encoding.Default.GetBytes(extractText)));                                                

            }
            sourceDocument.Close();
            reader.Close();

            return extractText;
        }
        catch (Exception ex)
        {
            throw ex;
        }