Data hiding in audio signal, video signal text and JPEG images

Steganography means hiding a message. Information hiding technique is a new kind of secret communication technology. Information hiding system uses multimedia objects like audio, images and text. Digital audio, images, text are increasingly furnished with distinguishing but imperceptible marks, which may contain a hidden copyright notice or serial number or even help to prevent unauthorized copying directly. Today the growth in the information technology, especially in computer networks such as internet, mobile communication and digital multimedia applications such as digital camera, handset video etc.