A specific frame is selected from a plurality of frames of moving image
data, and an initial contour corresponding to an extraction target is
generated in the selected frame. The initial contour is converged to the
contour of the extraction target. An initial contour corresponding to the
extraction target is set in an other frame on the basis of the result of
the convergence. Contour convergence to the contour of the extraction
target is effected on the basis of the set initial contour. As the other
frame, frames preceding and subsequent to the selected frame with respect
to time can be set.
