is it possible to modify a pdf with specific placeholder for image in order to insert an handwritten signature?
The idea is to have a placeholder, and when the user selects it will be prompted an input view.
This input view allow to handwrite the signature.
Could be this the right way, is possible to realize it with the library.
for ink annotation, just try demo "Ink" button.
for bitmap annotation, you shall use Page.AddAnnotBitmap() to create annotation.
the second point means you need map view point to PDF point by yourself.
bitmap annotation, can't modify, but you can remove and re-crate it.
for coordinate mapping:
assume you rendered a page to a bitmap object, then:
pdf_x = (x - bmp_x) / scale;
pdf_y = (bmp_height - (y - bmp_y)) / scale;