A content-dependent scan rate converter with adaptive noise reduction that
provides a highly integrated, implementation efficient de-interlacer. By
identifying and using redundant information from the image (motion values
and edge directions), this scan rate converter is able to perform the
tasks of film-mode detection, motion-adaptive scan rate conversion, and
content-dependent video noise reduction. Adaptive video noise reduction
is incorporated in the process where temporal noise reduction is
performed on the still parts of the image, thus preserving high detail
spatial information, and data-adaptive spatial noise reduction is
performed on the moving parts of the image. A low-pass filter is used in
flat fields to smooth out Gaussian noise and a direction-dependent median
filter is used in the presence of impulsive noise or an edge. Therefore,
the selected spatial filter is optimized for the particular pixel that is
being processed to maintain crisp edges.