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.