W3C home > Mailing lists > Public > w3c-wai-er-ig@w3.org > March 1999

Re: BODY Colors

From: Al Gilman <asgilman@iamdigex.net>
Date: Tue, 30 Mar 1999 13:00:16 -0500
Message-Id: <199903301756.MAA93911@relay.interim.iamworld.net>
To: "Leonard R. Kasday" <kasday@acm.org>, "Chris Ridpath" <chris.ridpath@utoronto.ca>, "WAI ER IG List" <w3c-wai-er-ig@w3.org>
If you can dig up your notes that would be great.

I have got Smith-Ketterwell to say they will help Chris a little.  That's
sorta the "buck stops here" point for visual perception AFAIK.

Al

At 12:02 PM 3/30/99 -0500, Leonard R. Kasday wrote:
>
>>The problem now is how do we quantify the colors. On your computer, the
>>colors are represented by 3 values (red, green and blue) and the values
>>range from 0 to 255. So what represents a poor visibility red? What values
>>make up a 'dark' background?
>
>The values are mapped to screen intensity in a non linear way, roughly. a
>power function.  v^gamma.  To make matters more complicated, gamma is
>different for Mac's, PC's, and some unix machines like SGI.
>
>In addition, the allowable contrast difference depends on the size of the
>text.
>
>I looked at this a while back and didn't find satisfactory quantitative
>data, even for people with "normal" vision.  
>
>We have the makings here of a good research project.  At least an update on
>the literature search I did.  Possibly some experiments.
>
>If someone wants to do a bit of research I'll be glad to dig up my old notes.
>
>Perhaps there are folks in the psychology dept up there who would like to
>look into this... viz. the folks in visual perception.
>
>Len 
>
>
>-------
>Leonard R. Kasday, Ph.D.
>Universal Design Engineer, Institute on Disabilities/UAP, and
>Adjunct Professor, Electrical Engineering
>Temple University
>
>Ritter Hall Annex, Room 423, Philadelphia, PA 19122
>kasday@acm.org        
>(215} 204-2247 (voice)
>(800) 750-7428 (TTY)
> 
Received on Tuesday, 30 March 1999 12:57:11 GMT

This archive was generated by hypermail 2.2.0 + w3c-0.30 : Thursday, 9 June 2005 12:10:32 GMT