I haven't written much about the technical side of HDTV lately, so an article is due. One thing I quickly discovered was that no one really seemed to explain HD in layman's terms. Articles were always too technical or so involved that I lost interest quickly. I hope this article is more to the point.
Two terms exist in the new wonderful world of HDTV that users should be familiar with - "up" conversion and "down" conversion. It's basically the process of going from low resolution video to high resolution video or vice versa.
Upconverting is the process of "upping" the amount of low resolution signal by adding pixels to fill an HDTV screen. For example, an upconverted DVD player is not true high definition like HD DVD or Blu Ray. It's still 480 lines of resolution, but uses a video scaling processor to create a picture that's almost HDTV quality. This is how you can watch regular movies on an HDTV using an upconverting DVD player. Other terms meaning the same thing include "upscaling" or "upsampling."
Downconverting is the process of taking higher resolution video and reducing the amount of pixels so you can watch video on a more traditional, lower quality device like analog TVs. The goal here is to keep the image from looking stretched or distorted. This is also referred to as "downscaling" or "downsampling."
On the broadcast level, we use professional converter boxes that work in the same way. Instead of adding pixels, we can add side panels or "flags" to video that is shot in 4X3 but aired in a 16x9 environment. We can fill the left and right sides of the screen with the filler image we choose.
Likewise, video shot in the 16X9 format during our newscasts is still seen properly on a 4x3 TV set using downconverters to take the center cut of 16X9 video and eliminating the extra space on the right and left hand sides without changing the aspect of the video itself.
The HD world is a very confusing one for the average person. However, learning a piece of knowledge here and there will eventually help to give you the overall picture in the few short years before this technology is forced upon us whether we are ready or not.
