As mentioned in the previous chapter, displacement vector measurement and its usage in motion compensation in interframe coding for a TV signal can be traced back to the 1970s. Netravali and Robbins (1979) developed a pel-recursive technique, which estimates the displacement vector for each pixel recursively from its neighboring pixels using an optimization method. Limb and Murphy (1975), Rocca and Zanoletti (1972), Cafforio and Rocca (1976), and Brofferio and Rocca (1977) developed techniques f