Hidden Technology, Based On The Number Of Video Streams

With the appearance of a large number of video products these years, technique has been asked not only to protect the copyright of them, but also to realize the safety communication of special ones. Though there are some papers on video hiding technique, most of them are focused on the protect applications, they are also called video watermark. Because of the limitation of their characteristic, video watermark technique has less hiding capacity , they can't meet the need of large data secret communication or information intercept controller. So, how to find a vedio scheme to realize large hiding capacity is very important for such applications.In this paper, three kinds of hiding technologies have been discussed and compared. After analyzing the characteristic of MPEG-2 and MPEG-4 encoding algorithm and MPEG coding system, a new hiding scheme based on video bitstream is presented and validated. Simulation results show that the proposed scheme has more hiding capacity without degrading the perceptive effect, and the information embedded can be retrieved lossless.In terms of the watermark approaches, we use the hiding idea of motion vectors as reference. To avoid the influences on the predicted images for incorrect operations to those motion vectors, we adjust the scheme on vectors selection and keep the change consistency of same moving objects' vectors. According to the picture structure of MPEG system, we hide data in different kinds of frame pictures adaptively. Because each data embedding will cause the change of coding stream length, we utilize the flexibility of coding structure and introduce a local coding restriction to control the stream changes in DCT data and motion vectors together, to cut down the changes as possible as we can. This not only keeps the consistencyof video compressed stream but also improves the hiding capacity. Finally, to get back the hiding information from a given video product exactly, a mark opinion is proposed, it can reduces the complexity of retrieving algorithm markedly and keeps the normal playing speed of video retrieved.