A new watermarking algorithm for scanned colored PDF files using DWT and hash function
Abdulqader Nael Mahmoud, Hamza Al Maharmeh, Hussain Al-Ahmad · 2015
This paper discusses a technique used to insert a watermark into scanned colored PDF files. The watermarking aims to protect the copyright ownership and authenticate the PDF documents. A logo has been used as a robust watermark for copyright. The logo will be embedded in the green channel of the file. This watermark can be successfully extracted and it can survive against different attacks. Any manipulations in the PDF file will cause the second fragile watermark to change and indicate forgery. The algorithm was successfully tested on different colored PDF files.