Color Transformations Based Computer-ART Mosaic Image

A mosaic image generation and transmission technique is proposed, which transforms automatically a given secret image into target image - called secret – fragment - visible mosaic image of the same size. The mosaic image, which looks similar to an arbitrarily selected target image and may be used as a secret image, is yielded by dividing the secret image into fragments and transforming their colour characteristics to be those of the corresponding blocks of the target image. Skilful techniques are designed to conduct the colour transformation process so that the secret image may be recovered nearly lossless. 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.