Databases Reference
In-Depth Information
F I GU R E 19 . 7
Top: Fields of a CCIR 601 frame. Bottom: An interlaced CCIR 601
frame.
format, the vertical resolution is first reduced by taking only the odd field for both the luminance
and the chrominance components. The horizontal resolution is then reduced by filtering (to
prevent aliasing) and then subsampling by a factor of two in the horizontal direction. This
results in 360
240 samples each of
U
and
V
. The vertical
resolution of the chrominance samples is further reduced by filtering and subsampling in the
vertical direction by a factor of two to obtain 180
×
240 samples of
Y
and 180
×
120 samples for each of the chrominance
signals. The process is shown in Figure
19.8
, and the resulting format is shown in Figure
19.9
.
×
