
Figure 29.13 Spatial
frequency spectrum of
composite
NTSC includes
luma, which spreads from
[0, 0], color subcarrier at
[188,240], and modu-
lated chroma, which
spreads from [188, 240].
Figure 29.14 Spatial
frequency response of
NTSC "notch" filter
shows that a large portion
of the luma spectrum is
wrongly decoded as
chroma. In areas of fine
periodic luma detail,
cross-color artifacts such
as swirling color rain-
bows are liable to appear.
Figure 29.15 Spatial
frequency response of
NTSC comb filter
exhibits greatly improved
luma response, and
reduced cross-color arti-
facts, compared to
a "notch" filter.
if any- that has been ...