A novel secure image coding scheme using fractal transformation

Lossy image coding by partitioned iterated function systems (PIFS), popularly known as fractal image compression, has become an active area of research. In this technique an image is encoded as a set of contractive transformations which represent the image compactly and produce an approximation to the original image. In this paper, we present a new application of fractal image compression in addition to obtaining high compression ratios and resolution independence. In particular, we present a novel secure image-coding scheme for still images based on encrypting some parameters in the contractive fractal transformation. This is done such that the end user or customer gets only a partially readable image of low quality. After being attracted by the image, he may access the full clear image upon request. In this case, the distributor will supply the customer with a simple key to retrieve the clear image from the low qualify one. The proposed technique is highly secure and, in addition, it provides a relatively high compression of the amount of information and bandwidth needed to transmit still images.