Image Hiding Application using Embedded Extended Visual Cryptography on Secret Natural Colour Image by Additive Colour-Space Distribution

Extended Embedded Visual Cryptography widens the concept of Visual Cryptography, by hiding or embedding the generated shares into host images, such that the original image may be reconstructed from these host images but by themselves, the images do not reflect the presence of the secret image thus making it in-detectable.In this paper, we intend to take up the challenge of Colour Image Cryptography, and implement it to find the most efficient algorithm or process for Visual Cryptography by comparing various existing cryptographic schemes and also some recent developments in the field of colour image cryptography. The secret image to be encrypted is first split into its three component shares based on the additive colour scheme (RGB) and then they are embedded into cover images so as to successfully hide them from unwanted viewers. The host images or cover images to be used are selected from a set of images in a gallery by comparing the respective colour space of the image with the colour space of the available images to be used as host. The images which provide the least distortion are selected to be encoded with the secret image data, and the host images are replaced with the embedded images in the gallery, thereby successfully hiding the secret image among the other images. Decryption is achieved by providing the hidden host images as key and reconstructing the secret image.