second corner region e 2 x are image blocks b c e the motion vectors vb vc ve of which are examined and used to generate a motion vector v 2 x of the corner region e 2 x in the manner explained above when these motion vectors vb vc ve form a homogeneous vector field with reference to fig2 b and the enlarged section in fig1 a third corner region e 3 x in the lower right corner of the image block x is formed by the pixels x 11 x 14 x 15 located in this corner adjacent to this third corner region e 3 x are image blocks e g h the motion vectors ve vg vh of which are utilized to generate a motion vector v 3 x of this third corner region e 3 x whenever these motion vectors ve vg vh form a homogeneous vector field as specified in the above explanations with reference to fig2 c and the enlarged section in fig1 a fourth corner region e 4 x in a lower left corner of the image block x is formed by the pixels x 8 x 12 x 13 located in this corner when generating a motion vector v 4 x for this corner region e 4 x motion vectors vd vf vg of.