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Progressive conversion method (page 77)
• Video based software conversion
Video shows an image by alternately
displaying every other line of an image (field)
at 30 frames (60 fields) per second (Interlace
format).
The Interlace format displays 30 frames (60
fields) per second by displaying every other
line of the image, causing scanning lines to
appear across the image. Since only half of
the image is shown at once, the amount of
information contained in an image is limited.
The Progressive format displays 60 entire
frames per seconds. The player accomplishes
this by converting each field into a frame by
using either a field-based conversion method
or a frame-based conversion method. The
appropriate method is automatically selected
by the player according to the movement of
the images on the screen. If the movement on
the screen is slow, the frame-based
conversion method borrows adjacent frame
information to fill in the missing information.
If the movement on the screen is rapid, the
field-based conversion method creates the
missing information by predicting the
movement of the images on the screen from
field to field. The end result is an image that
is higher in quality when compared to the
Interlace format.
• Film based software conversion
Film shows an image by displaying an entire
image at 24 frames per second. When you
watch a film on television, the television
displays every other line of the frame as a
field, thus reducing information level and the
clarity of the film image.
This player solves this problem by increasing
the speed at which the frames are displayed,
consecutively showing 3 identical frames
followed by 2 identical frames in the time that
it normally takes to show 2 consecutive
frames. The end result is that the 24 frames
per second are increased to 60 frames per
second, which is the speed at which
Progressive video signals are shown.
This not only allows film to be shown in a
frame based format, it also increases the
clarity and sharpness which is unique to
Progressive format images.
Compared to the Normal (Interlace) format
that alternately shows every other line of an
image (field) to create one frame, the
Progressive format shows the entire image at
once as a single frame. This means that while
the Normal (Interlace) format can show 25 or
30 frames (50-60 fields) in one second, the
Progressive format can show 50-60 frames in
one second. The overall picture quality
increases and still images, text, and horizontal
lines appear sharper. This player is
compatible with the 480 (525) or 576 (625)
progressive format.
Interlace pictures
Converted progressive pictures
Interlace pictures
Converted progressive pictures
