[Visual functions of
DVD-Video]
2. Picture quality good enough for professional users
Thanks to the adoption of MPEG2 digital image
compression technology, it is possible to achieve excellent picture
quality comparable to that of a studio master tape.
Compared to MPEG1 which is used for video CDs,
etc., MPEG2's image size is approximately 4 times greater and
the number of frames per second, 60, is double.
With video CD, the data transfer rate which
determines the picture quality is fixed at 1.15 Mbit/second, but
with DVD it can be set at maximum of 9.80 Mbit/second.
Moreover, adoption of variable bit rate makes
it possible for the transfer rate to be changed in accordance
with the degree of compression. Therefore, picture quality can
always be maintained at the optimum level, while at the same time
realizing efficient long-playback-time storage on a single disc.
Compared with video decks or laser disc players
aimed at the mass market, DVD achieves an image with less noise,
and that's true even for dark scenes. And because the resolution
is so high, outlines are clear, and an image with depth and presence
is achieved.
With analog equipment the image quality you
get basically depends on how much you spend. In contrast, with
digital technology excellent picture quality is attainable even
with low-cost equipment.