Recently, I am leaning graphics/image processing, such as adding annotation, creating watermark, etc. I include different image formats in my application, like tiff, png, jbig2 and so on.

Thanks for your sharing. Generating PDF document with a PDF add-on may be easier. Here is an example of generating, opening and saving PDF document.

Thank you! Based on my experience, some imaging functions still can not be realized with Photoshop. For example, I want to create a barcode image on the TIFF file or decode barcode from my TIFF image.

If you want to publish a PDF document file in web site, there are two factors that you may need to consider. One is that compared with HTML file, PDF file (a document format that can not be easily edited), is less searchable for search engines. The other is the crashing problem when user is visiting the PDF file using web browser. Thus, you can convert PDF document to html for quicker delivery to website. You may try this VB.NET PDF conversion control.