The motion estimation unit (100) comprises a block-matcher (102)
for calculating a start motion vector (110) by minimizing a predetermined
cost function as a matching criterion for the block (116) of pixels with
a further block of pixels (122) of a further image (120). The motion
estimation unit (100) further comprises an optical flow analyzer (104)
for calculating an update motion vector (111) based on the start motion
vector (110) and which is designed to find the most appropriate set of optical
flow equations corresponding to respective pixels of the block (116) of
pixels. This is achieved by analyzing gradient vectors of optical flow equations
for pixels of the block (116) of pixels. Finally the selector 106 of
the motion estimation unit (100) selects the motion vector (126)
by comparing the start motion vector (110) with the update motion vector (111).
