A method for automatically determining the region of interest from an
image comprises the three steps of (a) analyzing content of the
transformed coefficients of an image after a discrete signal
transformation and partitioning an image into the interested region and
background region that are based on p.times.p-pixel sub-blocks for
performing classification; (b) locating the central point of the
interested sub-blocks; and (c) integrating a plurality of the interested
sub-blocks from said central point to the boundary of an image to
generate a closed and continued region of interest by using a image
processing technique with considering the bit-rate requirement.