Also taking a similar view is Duan Yuren. In his view, the four programs of CVI, TVI, AHD and SDI will coexist for a certain period of time. “There is no question of who is better or worse. It may be that the leading companies are more willing to promote which one, and customers are more willing to accept which types of programs to determine the final pattern of the market. In terms of image effects, I am more optimistic about SDI. After all, it is lossless compression. However, its storage cost and engineering cost are also important issues to be solved.