We all see watermarks on music albums, books, on the images on the Internet, on the currency, bank notes, etc.

So, it’s quite natural to wonder what is a watermark? A watermark is a symbol embedded in an object to identity its ownership or its authenticity.

A digital watermark is a marker or a signal inserted into a digital file:

image

audio

video

document

These watermarks usually provide copyright information of the file. For example, a watermark for photos is a logo, text, or pattern that is placed over the picture.