Question: Hi-res (>640x480) capture from video]"
Nathan Urban
Hi all,
I would like to find a video capture card that will capture from an NTSC
video source at a resolution higher than 640x480. Digital vision used
to make a card (computer eyes 1024) that captured at 1024x512, but they
are out of business.
I have a hi-res (700 line) NTSC source and would like to digitize it
without losing any resolution. Does anyone know of such a product? or
does anyone know how to contact digital vision? (I tried to go through
focus enhancements as was suggested by the digital vision web page and
they were unable to help me.)
Nathan Urban
ur...@bns.pitt.edu
Department of Neuroscience
Don James
DPS Perception captures at 720 x 480, I think.
The DPS Hollywood captures and stores as uncompressed CCIR-601 AKA: D-1,
4:2:2:4, SMPTE 295, etc. That's as good as it gets.
--
Don James The Computer Room
Colorado's Desktop Video Specialists
2760 S. Havana St. Aurora, CO 80014
(303) 696-8973 http://www.ComputerRoom.com
d...@computerroom.com
_____________________________________
Nathan Urban wrote in message <3533EAA8...@bns.pitt.edu>...
ste...@nospamvoice.com
NTSC video, is for most intents and purposes 640x480.
720x480 (or486) is such because the pixels are rectangular. If you are
doing digital transfers to D1, you must have an aspect of 720x486 with
rectangular pixels. It's kind of odd.
The best you need for an NTSC signal is either one of these pixel
aspect ratios. 1024x512 is not applicable to this.
What you do want is something that can capture at very low compression
ratios, or high data rates. (same thing)
A 700 line source, is probably a D1, D2, or possibly a digital beta
source. The suggestion of going with a lossless video board such as
the Hollywood, is a good one. However, chances are pretty good that
you (the naked eye) will not be able to see a difference between the
orginal signal, and a signal cpatured by a board such as the dps
perception board, at 6 megs per second.
Nathan Urban
Don, stefan
Thanks for the recommendations. I new at all this, and a a bit fuzzy on the
standards, but
here are some more details on what I am trying to do. .
I have a camera (Hammamatsu C2400 Newvicon, B&W, analog camera) that has
(according to its specs) 700 lines of resolution and a composite output that
I can feed
(via coax/BNC) into a (video, not computer) monitor's NTSC input and get an
image. The image is much better when I feed it into a hi resolution
monitor (like the Dage HR-1000 that has 1000 lines of resolution) rather
than a more standard TV monitor. When I capture @512x512 resolution (Digital
Vision [www.digvis.com] Computer Eyes mono frame grabber) the image is not
as clear as when I capture @1024x512 (Digital Vision Computer Eyes/1024
frame grabber). Digital vision is out of business and so I can't buy the
Computer Eyes/1024 any more and I want a better image from my camera, but I
really only want B&W and single frames. So if I don't have to pay for color
or high frame rates, I would rather not.
So somehow it seems like there is more than 640x480x8-bits of information
to be gained from the analog video source. Is it that each horiz line can
be scanned
at an arbitrarily high rate and that this is how the higher resolution can
be gained? Thus the problem is the low sampling rate and pixelation in the
horizontal direction?
I would appreciate any information that people can provide.
Nathan Urban
ur...@bns.pitt.edu