Adding annotation in Pdf

How can I add annotation to an existing pdf file? I saw libHaru library.But it doesn't allow editin开发者_StackOverflow中文版g existing file. How can i overcome it?

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After running into this issue recently, I had to piece together a few ideas to make it work.

A few questions: What type of annotation are you doing? Do you have a png file of the pdf? What are you doing with the file after it is appended?

Hi-level: Convert pdf to image file either programmatically or before adding to the bundle. Have appending done and saved on another layer of the view (OpenGL as an example). Merge/Combine the two image layers. Draw new combined image pdf.