A new method for creation of secret-fragment-visible-mosaic image for secure communication

In recent years as many of our daily tasks are related to internet the security of information being transmitted over the internet is an important issue. Many applications or fields require transmitting secret image over the internet that may contain private and confidential information that is needed to be protected from hacker or from unintended users. Many techniques and methods have been proposed to ensure security, out of them most commonly used techniques are encryption and data hiding. Encryption ensures security but the problem with encryption algorithm is that the resultant noise image attracts the attention of hacker so it may be possible after many trials they can be decrypted by hacker. Another method is data hiding in which pieces of secret information is hidden behind a carrier that may be anything a text file, video, audio or an image. Now a day's, for secure image transmission a new concept that is of mosaic image is used in the field of data hiding. A new type of mosaic image that is called as secret fragment visible mosaic is formed to hide the existence of secret image by using a carrier image. In this paper a new technique for creating a secret fragment visible mosaic image is proposed, in which we select any random image of any size as carrier image for given secret image and by using this target image we arrange the titles of secret image to form resultant mosaic image and we performed reversible color transformation on mosaic image to reduce the distortion and also to recover the secret image exactly from the carrier image.