Improving the visual quality of secret fragment visible mosaic image

For security of digital images, an emerging technique is the use of mosaics of an image to construct an entirely different image. This is done by modifying the colour properties of a secret image in accordance with some reference image, i.e., transferring colour between mosaics of images. These mosaics are placed together to give an image that is similar to the reference image. This method is significant because it preserves all the 8 bits of all 3 colour planes and hence, can be useful for hiding highly detailed images. Here, there are two ultimate goals in view- make the final mosaic image more and more similar to the reference image; and make only reversible modifications to the secret image to achieve this desired similarity. This paper is focussed on improving the results of existing method to obtain a better final mosaic image. This will reduce the chances of drawing an attacker's attention. Also, different image sizes are studied in this work. The improvement in final image quality increases the scope of mosaic technique to smaller images as well. Details about this improvement are also presented here.