Watermarking

The book I read to research this post was Transactions on Data Hiding & Multimedia Security by Yun Q Shi which is a very good book which is a very good book which I bought from kindle. Watermarking & copy protection are almost interchangeable terms. Watermarking has many applications even data access. Even audio cds have watermarking next time you copy a cd look out for the message which says it's copyrighted. If you got taken to court for copying a cd that message which would be on the copied disc would be used to prove that you knew the disc shouldn't be copied. Many software have both watermarking & copy protection. When you copy the disc a similiar message to the one that appears for audio cds will appear. In addition you will probably have to set up an online account with a game service like steam which will check for the watermark. On a cdrom or dvdrom the information is in packets of 2 megabytes some games don't fill up all these packets with the result that if you try to copy it your computer gets confused. There is a way around this & that is by using a burnproof cd or dvd writer. Most cd, dvd & blu ray writers nowadays are burnproof. Watermarking can even be used with audio tracks where an algorithm puts a sound signal into a track. There's a relatively easy way of removing a watermark from a picture simply blur the part that contains the watermark. Sometimes you get specialist software that removes watermarks & these look at the result of the watermark & try to calculate the algorithm used. There's constantly a game of cat & mouse being played by the software houses & individuals trying to pirate their material pretty much like the world of viruses & computer security.