What is Digital Watermarking ?

Digital Watermarks are information embedded in digital data (such as images, text, sound, program code, etc.) so as to be able to retrieve it later for authentication purposes. Here the emphasis is on "hiding" information rather than "concealing" information, which happens in the case of cryptography. For this reason, it is also called as steganography (which means, information hiding).

In this talk we will focus on watermarking for images.

Key terms

Cover Object : This is the object that is used to embed the information into.

Embedded Information : The information that we need to embed.

Stego Object : The resulting object after the hidden information has been embedded.

Key : The key used to hide the information in the cover object, it is this key that we would use during the detection of the watermark.

Embedding : The process of hiding information.

Detection : The process of extracting the watermark from the stego object.

Attaks : Methods used to try and manipulate or destoy watermarks.