Lumagen Vision - Manual (Page 6)

Vision
™ User Manual and Installer Guide
© 2003 Lumagen, Inc. 3 Rev 1.13
Vision Functional Block Diagram
Composite and SVideo inputs automatically select between NTSC, PAL and SECAM
formats. The component input accepts standard-definition interlaced video. The selected
input is first sent to the TV decoder, which digitizes the video using a 10-bit analog-to-
digital (A/D) converter. The digitized data is then decoded into standard digital video.
The digital video is then deinterlaced into a progressive format. To accomplish this, four
input fields are used to determine the contents of each frame. For progressive sources, the
original frames are reassembled using 3:2, or 2:2, pull-down reconstruction. For video
sources, interlaced-video artifacts are detected on a per-pixel basis. Using the result of
this detection, the source pixels are combined into the best possible progressive image.
Proprietary scaling algorithms are used to scale the resulting progressive video to the
optimal size for the display. Unlike many video processors, which are limited to a few, or
even a single output resolution, the Vision is programmable from 480 to 1080 active
scanlines, in scanline increments. Output video is over-sampled to provide the best
possible image quality. Video oversampling provides the same benefit that audio
oversampling does for music CDs. That is, it produces the most-accurate reproduction of
the video signal possible.
As part of the scaling process, digital filtering is used to enhance the image detail. This
enhancement allows standard definition inputs, such as DVDs, to appear to be much
higher resolution, even when viewed on the large screen sizes common in home theaters.
Image enhancement combined with oversampling allows elements of the image to be
sharper and more precisely placed within the image. This leads to a more three-
dimensional look. In fact, a good way to judge the quality of any video processor and
display combination is to evaluate how “three-dimensional” the images appear for a
given video source. This is because edge enhancement makes the image appear to be
more focused, and improved edge placement gives better “depth cues” to the viewer.
When the digital processing is completed, video is once again converted to analog using
three over-sampled 10-bit digital-to-analog converters (DACs).
To accommodate the various video formats, the output type is programmable. It can be
set to YP
R
P
B
, RGBHV, RGBS or RGsB, with programmable sync type and polarities.
For the pass-through input, video is buffered using high-bandwidth video amplifiers. If
discrete sync inputs are used, they can optionally be converted to the same polarity as the
internally generated video sync outputs. This simplifies interconnection with displays that
require a specific sync polarity.
Critical display setup parameters have direct infrared-remote control key commands.
Other functions use an on-screen menu.
The composite, SVideo and component inputs each have two independent configuration
memories, to allow options such as day/night specific modes. These memories can also
be used to support two different sources on a single input, when external switching is
employed. If more than two sources are externally switched to a single input, it is