Regarding to “One touch scanning”, you can see the online solution developed especially for that purpose:
http://www.gnome.eu/Twain/examples/capabilities.html
You can find more information here:
http://www.gnome.sk/Twain/jtp_capabilities.html
Regarding to PDF:
Morena – Image Acquisition Framework for Java delivers scanned data via standard Java ImageProducer interface. So the task is: “How to save acquired data to the PDF file format, if the they are produced via ImageProducer interface?” It is the same task as if you produce image data from the image file. According the PDF file format, we have a feedback from our customers, that they have good experiences with iText, a free library for generating PDF files.
Here is a snapshot demonstrating how to save to pdf file using iText library:
TwainSource source = TwainManager.selectSource(null);
MorenaImage morenaImage = new MorenaImage(source);
Image image=Toolkit.getDefaultToolkit().createImage(morenaImage);
com.lowagie.text.Image iTextImage=com.lowagie.text.Image.getInstance(image, null);
iTextImage.setAbsolutePosition(0, 0);
Document document=new Document(iTextImage);
PdfWriter
writer=PdfWriter.getInstance(document, tmp);
document.open();
PdfContentByte cb=writer.getDirectContent();
cb.addImage(iTextImage);
document.close();But, you can use your preferable PDF libraries.
Martin Motovsky
Member of Gnome’s technical support