The invention provides a motion vector searcher which includes an
inter-block difference arithmetic operation section for calculating and
outputting difference amounts between an original image MB and a plurality
of search MBs, an additional amount arithmetic operation section for
outputting a correction difference amount obtained by adding an additional
amount, which relies upon a horizontal component and a vertical component
of each of the motion vectors and a state of coding, to each of the
difference amounts and for outputting a motion vector based on the motion
vector, and a motion vector determination section for determining an
optimum motion vector which exhibits the highest one of correlation
degrees between the original image MB and the search MBs. With this
arrangement, reduction of the information amount of motion vectors is
achieved when the compression ratio is high and the transmission rate is
low.
