RE: JPS?

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

P3D John W Roberts writes:
>One thing seemed a little ambiguous in yesterday's discussion of JPS:
>why do you need *shutter glasses* to view a side-by-side stereo image?
>Shutter glasses are normally used for sequential field or sequential frame
>stereo. It would seem to make sense if the video card takes the "side by
>side" images from the JPS data and displays them sequentially. But several
>people made a point of emphasizing that the display is not *interlaced*
>(field sequential). Does that mean the display is *frame sequential*,
>or something totally different? 

The side-by-side format (which, BTW, is oriented for cross-eye viewing)
does not REQUIRE shutter glasses, but provides a fairly simple means
of converting to various viewing methods, including anaglyph.  Shutter
glasses are, perhaps, the most common way of viewing stereo pairs on
a CRT because the resolution is too low to show small side-by-side
images clearly, while switching between views sequentially is quite
natural and easy for a CRT.

The Canopus system is frame sequential, as you guessed.  The software
separates the two images by dividing the width by two (thus JPS files
must have two identically sized images).  It would be possible to do a 
field sequential display from a JPS file, but each image
would have to be "shrunk" down to half height.

For those stereographers out there interested in CRT display of
stereo images, there are some interesting possibilities which I
would encourage you to try.  But I also caution that ghosting is
a bigger problem on most CRTs than you have with other 3D
viewing techniques.

Greg Marshall


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