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6.2 VIDEO NOISE REDUCTION SECTION
An advantage of digital processing of video signals is that
an FIR filter can be used to obtain flat phase characteristics.
And because S/N does not deteriorate even after processing
several times, it is advantageous after A/D conversion of
video signals with digital TBC to carry out processing as
much as possible digitally and to lessen analog processing
after
D/A conversion to obtain better picture quality.
This unit employs the PDB033A
as a high-quality field
coefficient DVSP (Digital Video Signal Processor) in the
last stage of the digital TBC
system.
This is directly
connected to PD5087, a 3-line direct matrix digital Y/C
separator IC. The DVSP acts as the core of this system.
Because video signal processing as well as character displays
is carried out digitally, it is possible to greatly reduce analog
circuits. The D/A converter is a single chip 3 channel D/A
converter which carries out D/A conversion of the Y and C
signals as well as the composite signal. The analog circuits
after
D/A conversion are basically limited to the amplifier.
CLD-97,CLO-98
Description of the Video Noise Reduction Block Diagram
This is then input to the NR block.
DIGITAL
YC
PD5087
Video Signal Processing Summary
101
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