Re: photos in the directory

[David Herron <[e-mail]>]

> JPEG is the new file format used for photos in the directory.  G3FAX is just
> Black & White (not grey scale or color) and is being phased out.

I haven't been following discussions for the photo's-in-directory discussion
but the demonstration I just got from my office mate has me concerned.  So
I've got some possibly naiive questions...

For the demonstration he had a particular picture JPEG'd and at 1024x768 pixels.
To display this with xv (recent version) took >30 seconds, and the command

	djpeg | ppmquant 256 >/dev/null

took 1.5 minutes.  (And it reported 30,000+ colors in the picture)  This was
on a lightly loaded Sun 4/490.

He wasn't sure about the gritty details, but was saying that JPEG always
uses 24bits/pixel.  To display on a monitor which don't do that many colors
you have to quantize it down to what your monitor'll do.  In my case (sun bwtwo)
that's 2 colors, while his (sun cg3) it is 256 colors.

But this seems weird.  JPEG is a recent standard, and comes after 3 or 4
generations of other picture formats.  Surely they woulda learned some lessons
and defined a format which allowed for lots of options.  Or maybe, since this
standard came from the Motion Picture industry, their concern was more focussed
on compression and high quality pictures and not on generality.

Q: What options are there in storing a picture?  Only in 24?  Other resolutions?

Obviously times-to-display of 30 seconds to 1.5 minutes (This does not include
any time involved with fetching through The Directory, since the picture was
already on local disk) is an unacceptibly long amount of time for the user
to wait to see the picture.  So I am concerned, suddenly, about whether this
was a good choice of picture format.

Q: What purpose is the photo stuff to serve?  Is it to store a persons picture
along with their Directory Entry?  Or is it to be for storage of pictures
in general, not necessarily of people?  The picture we were using wasn't (erm)
of the type that you'd want as your personal picture in The Directory, so does
the sort of picture & number of colors chosen &c make a difference to how
long it takes to display?

<- David Herron <[e-mail]> (work) <[e-mail]> (home)
<-
<- "Just because I recreate the middle ages on weekends doesn't mean I have to
<- at work." -- me