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il II
Figure
29.7
Dot crawl is exhib-
ited when saturated colors side-
by-side are subject to NTSC
decoding. Dot crawl is most
evident on the green-magenta
transition of the colorbar signal.
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I I
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Figure 29.8 Hanging dots are
evident when the colorbar
signal has been subject to NTSC
decoding by a simple two-line
nonadaptive comb filter.
image, comb filtering works well. However, to the
extent that either luma or chroma changes vertically,
chroma leaks ("crosses") into luma, and luma leaks
("crosses") into chroma. A decoder with a notch filter
will produce
cross-color
artifacts ...