A Review on Colour Image Steganography

Steganography is an art of concealing information in information. It is hiding data in data technique. The main purpose of steganography is to hide the existence of secret information. Traditionally encryption is used for communication security but it does not hide the very existence of secret data. So now day‟s steganography is more popular than cryptography. Many different mediums can be used to conceal the secret information, but the images are most popular because of redundant bits. For concealing secret data in image, there is large number of steganographic techniques and every technique has its own pros and cons. In this paper, broadly the technique can be classified under two of categories, first is spatial domain and second is Transform domain. This paper gives thorough understanding and analysis of different existing digital image steganography techniques of data hiding in spatial and transform domains. It integrates recent research work of various authors.