Re: Overlaying inline images

David Koblas ([email protected])
Fri, 18 Nov 1994 14:10:46 -0800 (PST)


> On Fri, 18 Nov 1994, Bob Kanefsky wrote:
> > Is there any chance that browsers in the future can be made to accept some
> > kind of overlay markup, specifying that two or more transparent GIF images of
> > the same size and shape should be displayed one on top of another as one
> > inline image?
>
> Better yet - is there an image file format that supports something like this
> natively? GIF95? If so, then it simply becomes another image format that a
> browser needs to/should support the inlining of, or shuffle off to an
> external browser.

GIF89a support multiple images, and even display methods for those
images nativly. The "transparent" information is a hack...

Transparancy in the GIF89a spec is defined as overlay information,
specifically onto the background image. True GIF files _always_
will have a background, not browser-defined... Belive it or
not it is actually possible to create 24 bit deep images using
the GIF specification, but that something that no display tool
will be able to support.

The GIF89a spec would allows you to do simple animation if you
wanted...

[email protected]

ps. I would take TIFF as a native browser image file format, yesterday!
* Supports 1 .. 24 bit images nativly
Colormapped, non-colormapped, etc.
* Supports multiple compression methods, None, LZW, JPEG.
* Supports transparancy
* Every real image processing, manipulation tool can write it.
* Image could contain copyright information
(GIF can only contain this information as a comment)