- From: Al Gilman <asgilman@iamdigex.net>
- Date: Tue, 30 Mar 1999 13:00:16 -0500
- 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 UTC