- From: Leonard R. Kasday <kasday@acm.org>
- Date: Wed, 03 May 2000 12:45:33 -0400
- To: w3c-wai-gl@w3.org
- Cc: w3c-wai-er-ig@w3.org
To WCAG copied to ER Image with sizes expressed in pixels can be a problem for a person with low vision because it can force an enclosing table cell to be wider than the screen when the user sets screen resolution low, e.g. to 480x640 (done to increase font and image sizes). Thus, the image, and other contents of the cell, lie off screen. At best, this requires horizontal scrolling. At worst, if the author has turned off scroll bars, those portions of the screen become unviewable. Now Checkpoint 3.4, which requires relative units, theoretically addresses this since image sizes... and coordinates of image maps... can be set as percentages, not merely pixels. However, with current browsers, presenting images at any size other then their natural pixel width can degrade their appearance because of aliasing, especially for fine detail. There's also the question of whether browsers have good support for image map coordinates set as percentages. Was 3.4 really intended to apply to image sizes and image map coordinates? If not, how do we handle this situation? One way, in wcag 2, is to simply say that screens shall read sensibly at any pixel resolution. Problem is, that may be overkill... does it apply e.g. to screens 48 x 64 pixels large. Ideas???? Len -- Leonard R. Kasday, Ph.D. Institute on Disabilities/UAP, and Department of Electrical Engineering Temple University 423 Ritter Annex, Philadelphia, PA 19122 kasday@acm.org http://astro.temple.edu/~kasday (215) 204-2247 (voice) (800) 750-7428 (TTY)
Received on Wednesday, 3 May 2000 14:03:40 UTC