PURPOSE: To reduce the transmission code quantity for the entire pattern by applying re-division only to a block having a large prediction error and trying motion compensation again.

CONSTITUTION: Retrieval is tried again so that a motion prediction error is minimized at quadratic conversion in a hexagon. Aa vertex 126 is noticed and three hexagons 120, 122, 124 using the vertex in common are selected to be object areas. The vertex is moved to a vertex 136 and a deformed hexagon is fixed in a timewise old picture. A prediction picture is generated by applying conversion so as to be deformed into original hexagons 120-124. That is, quadratic conversion is executed to the hexagons 130, 132, 134 and a motion prediction picture is generated from the hexagons and an average of the absolute values of the differences between the predicted picture and the picture to be predicted in the regions of the hexagons 120-124 is found and a motion vector of the noticed vertex 126 is obtained by the three step search so as to minimize the average value.