No Subject

[P3D Greg Marshall <greg.marshall@xxxxxxxxxxxxxxx>]

Shelley, Dan  writes:

>>Incidentally I tend to use the term "3D interlaced" to 
>>refer to images which are interlaced for viewing with 
>>LCS glasses.
>
>I am NO EXPERT by any means on this, but in my limited experience, 
>there appears to be a difference between JPS and older Interlaced 
>images on the web. Someone who knows, am I wrong?

"Interlaced" stereo derives from the interlacing that is used in
television where a frame is made up of two "fields", each con-
taining every other line.  Because older monitors could not
run at high enough refresh rates to avoid flicker when used
with shutter goggles (which effectively cut the refresh rate
in half), vertical resolution is traded off:  One field contains
the left view and the other the right view.  This works out
quite well, but is no longer necessary since modern mon-
itors can usually run at 120 Hz or higher.  A lot of stereo
images on the web are in interlaced form (one line of left
image, one of right, and so on) and so there are some
people who want to stay with that format.  But it has some
real problems.  For example, almost nobody uses inter-
laced display modes any more and many monitors and
display adapters don't support it.

JPS (JPEG Stereo) is not interlaced.  It is really just a
JPEG file containing two complete images, side-by-side.
Resolution is maintained, and construction or decon-
struction of a pair is easy to do with any image editting
software.

My company, Canopus Corp., manufactures the TOTAL3D
graphics board and is one of the companies promoting
this "standard".  We use it in our stereo viewing software.

Greg Marshall


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