- From: Ishida, Richard <Richard.Ishida@gbr.xerox.com>
- Date: Tue, 22 May 2001 18:37:37 +0100
- To: "'duerst@w3.org'" <duerst@w3.org>, Ian Jacobs <ij@w3.org>, clilley@w3.org
- Cc: w3c-wai-ua@w3.org, w3c-i18n-ig@w3.org
> (or width) than others. As the Latin script is rather at the lower > end (for upper-case only, a height of 5 pixels is enough), This is perhaps 'English' rather than 'Latin'. eg. Eastern European languages regularly use accents above and below capital letters, and would therefore require additional height. > > - What internationalization issues enter into this > > discussion? In case it is of use, here are requirements we came up with a couple of years ago with a customer re. minimum readable font sizes in pixels for a number of Asian languages. The minimum here is to allow reasonable representation of the complicated glyphs involved. Thai 7-8 pixels in width, but 22 pixels minimum height (because vowel signs below and above base characters, and tone marks above that. Korean 16 pixels square (includes a 1 pixel gutter vertically and horizontally) Japanese 14 pixels square (includes a 1 pixel gutter vertically and horizontally) (some strokes have to be sacrificed but context aids recognition) Traditional Chinese (Taiwan) 24 pixels square (includes a 1 pixel gutter vertically and horizontally) (this is obviously a lot, and is not needed for all Chinese characters, but there are a large number of very complex ones that do require 24 pixels for all strokes to fit. eg. ?[轟] ?[9F98] ?[9EA4] ?[9A6B] ?[7065] ?[91C1] ?[99A8] Note also that inter-line spacing may also be a factor - particularly in Far Eastern scripts. Two lines of 16x16 pixel ideographic characters separated by a single pixel gutter can be very difficult to read - plus the inter-line spacing generally helps indicate writing direction. Note that additional space may be required in the presence of underlined text. RI X______________________ Richard Ishida Globalisation Consultant, International Document & User Interface Design Xerox tel: +44 1707 353395 (Voicemail always available) http://www.xerox-emea.com/globaldesign/ > -----Original Message----- > From: Martin Duerst [mailto:duerst@w3.org] > Sent: 21 May 2001 07:50 > To: Ian Jacobs; clilley@w3.org > Cc: w3c-wai-ua@w3.org; w3c-i18n-ig@w3.org > Subject: Re: [Issue 512] Seeking lower bound on text size requirement > > > Hello Ian, > > Just a few thoughts: > > - There is two issues of resolution, namely a) the screen resolution > (in pixels) and b) the visual resolution (in terms of > optical frequency > per degree angle measured from they eye. > > For a), certain scripts may need more pixels for character height > (or width) than others. As the Latin script is rather at the lower > end (for upper-case only, a height of 5 pixels is enough), > you won't > get i18n problems, I guess (e.g. if the details for your checkpoint > say: "...control...size...of text down to at least 5 pixels...", > then that won't make it impossible for other scripts to > get to their > smallest feasible size). In other words, a tight (i.e. as high as > possible) lower bound requirement can differ for different scripts, > but you can just take the minimum, and the minimum for Latin is a > good overall minimum. > > b) is more difficult, because the UA software doesn't > really control it. > > - Being able to increase the reference size of rendered text > can also be > an I18N issue, as for some scripts, you really want to > make the reference > size larger. > > - The hight should be the overall hight, not the x-height. The aspect > ratio doesn't have anything to do with it as far as I understand. > > - Please note that there are programs (mostly layout software such > as pagemaker,...) that show a line of text below a certain size as > a grey strip. This is called 'greek text' (as always, typographers > use strange terms :-). This can be quite helpful to get an overview > of a large page, less disturbing that actual text that is too small > to be read, but I'm not sure it's an accessibility issue. > > > Regards, Martin. > > > At 11:21 01/05/18 -0400, Ian Jacobs wrote: > >Chris, Martin, > > > >The UAWG would like your input on a question of visual text > >rendering and internationalization. Checkpoint 4.1 of the 9 April > >2001 draft [1] starts: > > > > "4.1 Allow global configuration and control over the reference > > size of rendered text ..." > > > >This is a Priority 1 checkpoint. One reviewer pointed out that it > >is not really a P1 requirement to allow the user to choose very > >small text sizes. Indeed, the intention of this checkpoint is > >primarily to allow users with low vision to increase text > >size. [I would note here that small text is useful to some users > >(e.g., so that users with screen readers can scroll less), but > >that's not a P1 requirement.] > > > >At our teleconference yesterday we asked ourselves whether we > >could come up with some lower bound on the requirement. Thus, > >user agents would not be required to provide access to very > >small text size as part of meeting this checkpoint (or, > >for example, they might allow configuration, but not > >actually be required to render very small text). > > > >Our questions are thus: > > > > - How might we express a lower bound in text size? > > What units would we use? What parameter to measure > > size (x-height? aspect ratio?)? > > > > - What internationalization issues enter into this > > discussion? Does a lower bound requirement > > make sense across different scripts? > > > >Thank you for your help on this topic, > > > > - Ian > > > >Note to the Working Group: For checkpoints 4.1 and 4.2, we should > >change "rendered text" to "visually rendered text" to be more > >precise. > > > >[1] http://www.w3.org/TR/2001/WD-UAAG10-20010409/ > >[2] http://server.rehab.uiuc.edu/ua-issues/issues-linear-lc3.html#512 > > > >-- > >Ian Jacobs (ij@w3.org) http://www.w3.org/People/Jacobs > >Tel: +1 831 457-2842 > >Cell: +1 917 450-8783 >
Received on Tuesday, 22 May 2001 13:41:00 UTC