DigitalVideoAndHDTVAlgorithmsAndInterfaces.pdf

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Figure 37.15 [1, 4, 6, 4, 1] transverse
filter implementation
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Figure 37.16 Interstitial
spatial filter implementation
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LINESTORE
chosen, each of these transverse filters can be implemented
using the structure shown in Figure 37.15
above, which employs three registers and three adders.
The [2, 8, 12, 8, 2] filter is identical, but has its final
sum shifted left one place to accomplish the multiplication
by 2.
The 2-line spatial filter of Figure 37.13 can be implemented
using a linestore, two [1, 4, 6, 4, 1] transverse
filters, and an adder, as shown in Figure 37.16 below.
The 3-line spatial filter of Figure 37.14 can be implemented
using two linestores, three [1, 4, 6, 4, 1] transverse
filters – one of them having its result doubled to
implement coefficients 2, 8, 12, 8, 2 – and two adders,
as shown in Figure 37.17 at the top of the facing page.
A simple adaptive filter switches from interframe averaging
to interfield averaging when the motion estimate
exceeds some threshold. However, abrupt switching can
result in artifacts: Two neighboring samples may have
very similar values, but if one is judged to be stationary
and the other judged to be in motion, the samples
computed by the deinterlace filter may have dramatically
different values. These differences can be visually
442 DIGITAL VIDEO AND HDTV ALGORITHMS AND INTERFACES
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(2, 8, 12, 8, 2)
TRANSVERSE FILTER
(2, 8, 12, 8, 2)
TRANSVERSE FILTER
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