Sony RDR-GX7 - Manual (Page 24)

Post processing to obtain the highest
possible image quality from the disc
The RDR-GX7 has been designed not only to be a superior DVD
recorder, but also to offer a complete array of playback functions.
Sony's flagship model DVD player the DVP-S9000ES, released
towards the end of 2000, was used as a reference in the planning
and design of the RDR-GX7. Accordingly, the DVP-S9000ES
contributed much of the high level digital technology adopted in
the RDR-GX7 for high quality images, along with other
technologies developed specifically for top class performance
befitting a flagship model. Both commercially available DVD
software, as well as DVD discs recorded by the RDR-GX7, can
be played back with the same high level of quality offered by
Sony's finest DVD players.
■ Precision Cinema Progressive
Sony’s Precision Cinema Progressive system achieves clear and
beautiful output from all types of recorded discs, including DVD
software titles as well as discs recorded on the RDR-GX7 itself.
This system employs several key technologies, including Pixel-
by-Pixel I/P Conversion and V-Edge Compensation, along with
advanced video D/A converter with high bit rate and sampling
rate for enhanced performance. The following explains these
technologies in detail.
Pixel-by-Pixel Active I/P Conversion
In progressive video, the pairs of video fields of the interlace
system are combined (in a process called I/P conversion) to
create a single video frame. Since twice the number of horizontal
lines result, a more finely detailed video image is obtained.
While a pair of fields are combined into an image, depending on
whether the original source was originally created on film or was
shot with a video camera, this process is performed in an entirely
different manner. Sources originally created on film are made up
of a series of still images (film frames), so the two fields are
created from the same frame in order to obtain a highly precise
image. However, most sources created with a video camera are
shot in field units. Time elapses between these fields, so if they
are simply combined into a pair, the resulting video image
becomes blurred. This is particularly noticeable during sequences
with rapid movement.
Since the RGR-GX7 is expected to be used mostly to record
programming which originates as video images, Sony has
incorporated Pixel-by-Pixel I/P Conversion. This technology
assures the highest possible image quality when playing back not
only film sources but also non-film sources such as television
programs as well as content recorded using various types of
camcorders.
Fortunately, all video images in a video sequence or program are
not entirely composed of movement. For example, in car chase
scenes, while the cars are moving quickly, buildings and the
surrounding scenery remain still in relation to them. Therefore,
by separating the moving elements in a scene from those which
are not moving, separate forms of video processing are possible.
This is the concept behind Sony’s Pixel-by-Pixel I/P Conversion.
The images of the three previous fields are stored in memory,
allowing comparison with the current field. In a given image, if
the current odd-numbered frame’s image is the same as a
previous odd-numbered frame’s image, there is a high
probability that this part is a still image, but if it is different, then
this part is judged to be a moving image. Thus, in Pixel-by-Pixel
I/P Conversion, for pixels judged to be part of still images, pixels
from previous even-numbered frames are selected. For pixels
judged to be part of moving images, interpolation data is created
based upon the horizontal lines above and below the current odd-
numbered field image. In this way, Pixel-by-Pixel I/P Conversion
assures clear and beautiful progressive conversion of images
originally created on video.
Chapter 4-4
High quality
image & sound
RDR-GX7 Technical Notes
24
Still area processing Moving area processing
Still processing
Still Part
Moving processing
Moving
Current field
Past field
Current field
Past field
Simplified Represenation of Pixel-by-Pixel Active I/P Conversion Operation