| Title: | DECWINDOWS 26-JAN-89 to 29-NOV-90 |
| Notice: | See 1639.0 for VMS V5.3 kit; 2043.0 for 5.4 IFT kit |
| Moderator: | STAR::VATNE |
| Created: | Mon Oct 30 1989 |
| Last Modified: | Mon Dec 31 1990 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 3726 |
| Total number of notes: | 19516 |
I know this is not a hw specific conference, but I'm just checking
if someone could help or give me "yet another pointer" ;-)
We have a customer with a very special need for graphics. Here is his
mail which explaines his problems ...
Question is if our PXG HW could solve his problem ?
- what is resolution of DACs used in our DS5000-200PXG ?
- can we use some lookup table between colormap and DACs ?
+----
From: [email protected]
Newsgroups: comp.graphics
Subject: Workstation with HiFi color wanted (24 bit's not photorealistic)
Message-ID: <[email protected]>
Date: 11 Oct 90 01:40:09 GMT
Organization: University of Helsinki
Lines: 35
I am looking for a graphics workstation or frame buffer which is capable to
produce more intensity levels on screen than normal ones. It is intended to
be used to produce precicely controlled visual stimuli for our vision
reseach measurements. The normal 24 bit full color definition is absolutely
not good enough. 48 bits i.e. 16 bits for every color component would be quite
optimal. In addition to it there would be gamma correction lookup tables
16 bits in and something more out to make things right for High Fidelity
imaging. All that should be double buffered and/or there should be enough
bandwidth between frame buffer and memory with some locking system to make
smooth animation possible.
Indexed color 3 x (8 bits to something more) is better than plain 24 bits
if direct color systems with enough bits are not available. This can be
done with gamma correction lookup tables if they have bigger outputs than
inputs and DACs have enough bits too. I am interested to get information
of grayscale systems with high intensity resolution too.
I already know that Evans & Sutherland has 9 bits DACs in some product
and Pixar has 10 bits output but these are not enough. But who has more?
12 bits per color component is about the minimum but not yet perfect.
So the digital to analog converters should be at least 12 bits for each
channel. If there is no more than 12 bits then dithering must be used for
additional fine tuning and gamma correction must be calculated to the image
file, which both take additional processing power.
If somebody can help me to find such a High Fidelity graphics workstation
or something near it please do so!
Kari Osmoviita [email protected]
University of Helsinki
Department of Physiology
Vision Research Laboratory
Siltavuorenpenger 20 J
SF-00170 Helsinki
Finland
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 3467.1 | Question: Does CRT performance become the limiting factor? | IO::MCCARTNEY | James T. McCartney III - DTN 381-2244 ZK02-2/N24 | Wed Oct 24 1990 01:53 | 18 |
While I don't claim to be anywhere near "expert" on this subject, I'm
left to wonder where they expect to find monitors with phospors which
are capable of producing such fine differences in intensity.
Additionally, the primary colors used for most monitors are nowhere
near the edges of the CIE chromasticity horseshoe, so regardless of the
number of bits of resolution, there are some visible colors which just
can't be produced.
Does this customer really understand the physics of CRT displays
sufficiently to know his assumptions about DAC width will actually
cause a MEASURABLE difference on the screen?
Sounds pretty strange to me.
James
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