Re: B/W Camera problems W/cu-seeme/win?

Thomas P. Donahue (tdonahue@dsys.com)
Tue, 3 Jan 1995 19:47:37 -0500


> Just got a Media Vision Pro Movie Studio board very cheap, which seems to
> work with cu-seeme except for one big problem:
>
> It seems to display only two shades of gray, white and kinda gray, and the
> picture is unusable. Contrast works over a limited range. VfW images look
> fine, albeit a bit dark at 256 palletized.

Steve I also bought a cheap Pro Movie Studio board (Surplus Software -
$99!!), and have the same problem. BTW, when using Video for Windows
Capture, if you capture a frame or two into the pallette, the image
will brighten up quite a bit. (at least it does with mine)

> Naturally, I have done the obvious things, the vid is 160/120 256 color
> palletized, my video driver is 256, and so on. I suspect the routine in
> cuseeme that builds the pallette may be getting freaked out by the lack of
> color input, which is strange, because it is an easy case.
>
> This is an extreme drag, because I bought a very nice B/W camera cheap for
> this purpose. I know where I can get a very nice CCD B/W cameras W/power
> supply, about the size of a pack of cigarettes, in a case looking good for
> $90.00.The cu-seeme version is 34b4. If possible I will bring in a color
> camera and try again. If this really is a software problem, it shouldn't be
> hard to fix, as a B/W palette could just be coded in!
> (0,0,0,1,1,1,2,2,2,3,3,3 or 0,0,0,64,64,64,128,128,128,192,192,192,192)
>
>
> Anyone with ideas, please email me or post a reply w/comments ASAP.
> Steve Loboyko

Although quite normal in VFW, my CU-SeeMe image (and yours I suspect)
was negative. I found a cheap video mixer/effects box that could
invert video. When I hooked it up, and restored a positive image, it
then became more obvious that the image was only a 1-bit mono, or at
best, a bad 2-bit "grayscale" image.

To me, the CU-SeeMe documentation seemed a bit ambiguous. It says
that any board that works with VFW should work, as long as you can set
it to use 8-bit pallettized, uncompressed images at 160x120. I later
noticed in the Help screens, something to the effect that CU-SeeMe
currently uses 4-bit gray scale (not 8?!).

I have no idea what format the data is in or should be in. But, if
it's really only using 4 of the 8 bits, perhaps our driver supplies
the data such that CU-SeeMe is grabbing the least significant nibble
instead of the most significant nibble, or something along those
lines. I sure wish I had the source code! The PMS is so much cheaper
than the Video Spigot or Video Blaster, that it would be worth it to
hack on the source for a while to try to fix this. Does anyone know
if the source code is available somewhere?

BTW, for those who can't afford a new video camera or can't tie up the
household camcorder, check your local electronics/Ham swap meets. Now
that everyone has switched to CCD technology, the older, somewhat
bigger (but still small) surveillance cameras can be purchased very
inexpensively. I'm using some cameras that I picked up at a Hamfest
for $10 each (they're not for sale) that work just fine.

Regards,

Tom