- From: David Woolley <david@djwhome.demon.co.uk>
- Date: Sun, 15 Dec 2002 11:42:04 +0000 (GMT)
- To: w3c-wai-ig@w3.org
> the outlines of image links are helpful for identification, I mis-read this at first as being a plea not to turn off the (typically) blue border on images within anchors (which would certainly reduce the hunt the link problems on many pages), but I think what is really being talked about here is using the profile of an image, rather than its internal structure, to recognize it. Note that HTML has no concept of an image link, only an image with an associated link; certainly no concept of icons (icons are essentially a presentational concept, or an alternative - ideographic - language version). > Can we make a guideline that image links* should ideally have > transparent backgrounds, and non-rectangular** outlines? (W3C please > note) If these help recognisability, commercial web sites will do it anyway; they are the sorts of things that marketing departments do ask for. In fact, particularly on youth market sites, they are the sorts of thing I would expect to see over used. Howver, the reality is that good transparent backgrounds on all but the simplest icons requires full alpha channel support, in practice PNG at the moment. PNG has generally been ignored by commercial designers++, who don't care about the patent issues, and probably don't have the technical understanding to see benefits over GIF. If you are preparing an apparently transparent company logo using GIFs, you can only anti-alias it - necessary for images that are not specifically designed to be pixelised - if you do so against a background that nominally matches the target background. Such logos, although having transparent borders, show a halo of the nominal background colour when shown against a different background. Obviously SVG vector graphics should suffer this problem as they have edges that are not pixellated. > and failing on transparency have backgrounds that are easily changed? The background may well be part of the corporate image. Actually, the fact that the background colour is likely to be part of the overall design is probably the main reason why there is no incentive to move to image formats that support anti-aliasing of transparency. > *presumably most sites are happy to be linked to, so why is it that so > few images used as links are appropriate for sharing? Most commercial sites are not happy with arbitrary linking. In particular, most do not like deep linking (I think you may be getting away with deep linking entertainment sites only because you are not taking away an audience that they want, and taking legal action against charities always risks bad press==). Even for linking to home pages, many sites would rather only be linked from reputable sites. When it comes to icons, these are trade marks. Companies are very jealous about guarding their trade marks, as use by other site can imply some level of approval. Most big companies have legal documents explaining when trade marks can be used, and exactly how they can be used. (Generally, trying to emulate a trademark is even worse an offence than using the official design without permission.) > **wondering what others feel about the rather heavy handed cartesian, > or western imperialist insistence on boxes? Most strokes in Chinese characters are horizontal or vertical, often forming boxes. The whole of each character is expected to fill a, constant sized, square box. I'd hardly say that boxes and rectilinear structures were a western cultural imperialism thing. (I'd be more concerned that Chinese language web sites use on the text as graphics, tiny fonts, poor colour contrasts, and generally bad markup, of western sites, indicating that they are cut and paste coding such sites in the same way that most Western authors cut and paste code.) Rectinlinear structures are used because they are technically easier to support (general accessibility) and because they introduce an element of order into the design that helps people find their way around. ++ Support in major browsers has been broken and partial, as well, which more or less guarantees that they will be ignored by designers. In particular, I don't think that original implementations included the alpha channel. == You mentioned the BBC; they are probably exceptional, as they still retain some level of public service ethic - most entertainment sites are just vehicles for advertising.
Received on Sunday, 15 December 2002 06:42:39 UTC