How to set ImageFileType for Image

Hi Team,

 I am getting image as bytes from  database and that bytes may be of a png or jpeg mage.

How can  specify the ImageFileType for an Image control in pdf.

       Document pdfDoc = new Document();

       pdfDoc.getPageInfo().getMargin().setLeft(10);

       pdfDoc.getPageInfo().getMargin().setRight(20);

       pdfDoc.getPageInfo().getMargin().setTop(10);

       pdfDoc.getPageInfo().getMargin().setBottom(10);

       pdfDoc.getPages().add();

Image img1 = new Image();

       img1.setFixHeight(50);

       img1.setFixWidth(50);

ByteArrayInputStream bstream = new ByteArrayInputStream(bytes);

       img1.setImageStream(bstream);

       pdfPageItem.getParagraphs().add(img1);

       pdfDoc.save("Sample.pdf");

Thanks

Leena Robert