Re: Question....

[o9938156@unicorn.it.wsu.edu (mark lyon)]

Nathan Mates (nathan@visi.com) wrote:
: In article <01bcadc5$2af6a120$LocalHost@default>,
: Tim in Town <timf@rmi.net> wrote:
: >>     It sells for US$149.95 for the 24-bit/1 MB version. Yes, it
: >> is an SVGA video card for the Apple IIgs, but relatively nothing
: >> out there supports it (just a handful of graphic viewers). 

: >So, I won't get the same image quality (from a JPEG, for example) on a
: >Second Sight enhanced GS as I would on a standard PC?  Is this right?  If
: >so, what's the point of having a Second Sight card?

:     With the 24-bit SS, and a good (and that's one of the sticking
: points; I don't own a SS and haven't seen one in action) SS-specific
: Jpeg viewer, you might be able to get an identical picture out of that
: and a PC.  However, it's likely to be a hundredth (or worse) of the
: speed in decompressing the file.

Depends on the speed of the PC ;)

AFAIK, the only two SS aware jpeg image viewers (SecondView Pro and
jpeGS) will display the images in 16 bit color, or 32,768 colors.
The SS is a 24 bit capable card, but thanks to Sequential's amazing
non-support, only 16 bit modes were programmed into the card.  So the
image output of a 24 bit capable PC will be better than the 16 bit
image on the SS.  OTOH, a 16 bit image is usually _much_ better
looking than a 16 color image.
 
:    As the output from two properly implemented Jpeg viewers should be
: identical at 24-bit color, it's mostly a question of whether there
: exists a 24-bit Jpeg viewer for the SS. 

Actually, depending on how the inverse discrete cosine transform is
implemented, the image may be _slightly_ different between viewers.
The reference would be calculated using floating point math (preferably
double precision), but few viewers would actually do so because of the
speed penalty.  The use of integer math in the IDCT will introduce
small roundoff errors that could possibly change the image, but
probably not very noticably.

:    The major appeal of the SS is being able to connect to the
: thousands of [S]VGA monitors out there for hopefully a larger screen;
: if all you're diong is displaying text, some people prefer the
: boldened PC text font as being easier on the eyes.

: Nathan Mates

Mark Marr-Lyon