Multistage SDTV/HDTV scanning rate converters

SDTV/HDTV conversion has several applications of current interest, such as pyramidal coding for simultaneous SDTV and HDTV output, HDTV display of SDTV signals, and SDTV display of HDTV signals. The effectiveness of multistage filters in this application is established. The design of the filters to use in these configurations is a delicate issue, since it has to balance several, and sometimes conflicting, requirements. The design objectives depend on the specific application, and are ultimately targeted to the visual rendition of the system. These objectives do not fit traditional design specs and call for provisions of visual significance in both the frequency domain and the spatio-temporal domain. This work reports on the findings of some systematic research on this field