Unique Image Transmission Technique Through Secret-Fragment-Visible Mosaic Images By Approximately Reversible Colour Transformations With High Security

Abstract

Unique image transmission technique is proposed, which transforms automatically a given large-volume of secret image into a allegend secret-fragment-visible mosaic image of the same size. The mosaic image, which looks similar to an swiftly selected target image and may be used as a masquerade of the secret image, is generate by dividing the secret image into fragments and transforming their colour characteristics to be those of the corresponding blocks of the target image. Skillful techniques are designed to conduct the colour transformation process so that the secret image may be recovered nearly losslessly. A scheme of handling the overflows/underflows in the converted pixels’ colour values by recording the colour differences in the untransformed colour space is also proposed. The information required for recovering the secret image is embedded into the created mosaic image by a lossless data hiding scheme using a key. Good experimental results show the feasibility of the proposed method