A method is provided for encoding K1 sequentially presented video pictures.
Each of the K pictures is divided into an m1 rown1 column array
of non-overlapping coding units of equal sizes. Each coding unit occupies a respective
coding unit position in the picture from which it was divided. An arbitrary, pseudo
random pattern of coding units is selected for refreshing during each of the K
pictures. Each pattern selected during any given one of the K pictures includes
a sequence of one or more coding units of the array. In addition, the pixels of
each coding unit selected for refreshing during a kth picture occupy
different pixel positions than each coding unit selected for refreshing during
a preceding one of the 1st to (k-1)th pictures of the K pictures.
Furthermore, each pixel position of a moving picture image formed from the K pictures
is selected for refreshing once over the sequence of K pictures.
A system for encoding includes a source of the K pictures and an intra/inter
circuit for selecting the coding units for refreshing over the sequence of K frames.
The method or system produces an encoded signal which can be stored on a storage
medium. A method and system for decoding the encoded signal is also provided.