A (50) method and apparatus (110) for determining a scanning format of a
frame of a video signal determines (52) if any interfield motion exists
within the frame; and indicates (53) that the frame is interlaced scanned
if interfield motion is detected and indicates (54) that the frame is
progressive scanned if interfield motion is not detected. The
determination is based on spatial correlation within and around one or
more edges of one or more objects in the frame. This can be accomplished
by identifying zig-zag or zipper effects near one or more edges of one or
more objects in the frame, identifying motion between fields or
identifying motion near one or more edges of one or more objects. A
method (100) for determining a field order of two interlaced frames of a
video sequence of frames assigns (101) one of the two interlaced frames
to be a first frame and the other of the two interlaced frames to be a
second frame and assembles (102) two new frames from the two interlaced
frames by combining a bottom field of the first frame with the top field
of the second frame and by combining a top field of the first frame with
a bottom field of the second frame. The number of zipper points in each
of the two new frames is then determined and compared. If the number of
zipper points in the first frame is smaller than the number of zipper
points in the second frame, that the field order of the two frames is top
field first, otherwise the field order is bottom field first.