In the past, I know that Toshiba and Sony players did it differently. Toshiba removed 1 of 4 lines, and Sony did something else that I can no longer recall.
"Now when you process the video to create an anamorphic picture, you use a process called upsampling (or interpolation) to generate additional lines of video. The upsampling algorithms used - bicubic, lanczos, etc. - are much more sophisticated than simply doubling up certain lines or using linear interpolation. The aim is to increase the size without blurring the edges too much or producing jaggies, and these algorithms do this sucessfully (lanczos is said to be sharper, but I don't really notice a difference between bicubic, lanczos, Mitchell, sinc or any of the advanced upsampling filters).
So when you watch a letterboxed DVD, you see a stretched out picture. When you watch an anamorphic DVD, you see an upsampled picture. I don't need to tell you which looks better."
Hopefully, people won't confuse this with an anamorphic picture made from film, which doesn't require this upsampling. Anamorphic video made from a letterbox transfer looks nowhere near as good as anamorphic video made from a film source. Does anyone know what "algorithm" Dr. Gonzo used when he made his transfer?
In any case, the few anamorphic transfers I've made from the SW LDs always show the inherent flaws much clearer than a straight letterboxed transfer I (and I've recently seen that there are many more than I originally knew of, and they actually get worse as the quality of your player improves.
)