Image decomposition for selective encryption and flexible network services

We propose a novel image and video preprocessing technique (edge and residuum decomposition - ERD) that mainly concerns the decomposition of the image into three separate components: edge location; gray-tone or color inside the edges; residuum "smooth" image. While the residuum image is compatible with any natural-image encoder, new algorithms and solutions are introduced to achieve a compressed description of the edge-based information; the overall occupancy is comparable to that yielded by traditional image and video encoders. Both qualitative and quantitative results are shown, as well as an analysis of the separate components. Since all the components (edge position, edge color and residuum) are needed to completely describe the image, whilst some of them are particularly critical to recognize (and "preview") it, the proposed solution enables new encoding services, mainly selective encryption; just hiding edge positions leaves a perceptually meaningless image unencrypted.