JuntaoXiao/PDF-electronic-signature

PDF electronic signing: generate a handwritten-style signature image, stamp images and typed blocks onto PDF pages, and apply a PKCS#7/CMS digital signature with a PKCS#12 certificate you supply. Stamping first keys an opaque background out to transparency - un-compositing each pixel so the ink keeps its original colour - and trims to the ink, so a seal stamped over a signature does not erase it.