Delivery method for viewer-specific privacy protected video using discrete wavelet transform

This paper presents a delivery method for viewer-specific privacy protected video, where “viewer-specific” implies that the way of privacy protection (e.g., box, mosaic, transparency) varies according to viewer's authority. In this method, in order to reduce the load of a delivery server, viewer-specific privacy protected videos are not produced at the delivery server, but they are produced at each viewer's terminal. The delivery server extracts and decomposes the information of human objects, and then embeds the information into background images using information hiding technique. Each viewer extracts a part of the decomposed information of human objects according to his/her authority, and then produces privacy protected video by integrating the extracted information. In this method, the discrete wavelet transform (DWT) plays a key role. The proposed method is evaluated through experiments.