From: Kjetil Torgrim Homme <email@example.com> Date: Tue, 4 Apr 1995 14:16:49 +0200 Message-Id: <firstname.lastname@example.org> To: C.J.Osborne@sheffield.ac.uk Cc: email@example.com In-Reply-To: <1F7685339B1@ramsley.shef.ac.uk> (C.J.Osborne@sheffield.ac.uk) Subject: Re: Transparancy [Christopher J. Osborne] | One thing Netscape information providors can do is to make the | transparent background colour of their gifs light grey (ie RGB | value of 195,195,195). I know this makes it a little more | difficult to make sure the gif is actually transparent, but as | most other browser use this as a back ground colour, you will | greatly increse the chances of you transparent gifs still looking | good in other browsers (and I don't just mean Mosaic. I do this myself, as a remnant from when the current Mosaic version didn't support transparency. Unfortunately, most transparent gifs assume that the background is some shade of grey. You see this most clearly in the edges, where the black fades to gray. If you for some reason choose, e.g., a dark blue background, there will be a light halo surrounding the graphic. For this reason, one should be critical of what graphics one makes transparent. Fortunately, the upcoming PNG format will have gradual transparancy on any colour, and even a full alpha channel if needed. [Phillip Hallam-Baker] | What would be nice would be to have a pixmap type affair such that | the drawing was stated as being in the foreground and backround | colours of the screen. Thus the text colour would match the | picture text colour. | | Something for the new Gif standard perhaps?? Yes, this would be nice. There already is a "bKGD" which specifies a suitable background colour for the viewer, if doesn't have one already. fRGD Foreground color This chunk specifies that the given color in the image can be presented as the overall foreground color in the viewer. [Adapt the text for the bKGD chunk for the details.] We don't need the background corresponding information, since transparancy handles that nicely. An alternative is to use greyscale images and let the browser change what black and white means, however fans of white lettering on black might not like that :-) Does anyone know the address to the PNG mailing list? Kjetil T.