Message-Id: <mailto:199507171442.JAA12775@library.wustl.edu> Date: Mon, 17 Jul 1995 09:40:00 -0500 From: mailto:MARTINA3558@UNI.EDU> Subject: Re: GIF inline images in WWW pages To: Multiple recipients of list IMAGELIB
In response to the following:>I have been doing some reading on browser support of GIF images and there
>seems to be a lot of advice (which I think may be erroneous) that if one
>uses fewer colors in a GIF image for inline display the file will be
>smaller.
This depends on how you interpret the phrase "fewer colors"
I've done some experiements with a single image, in order to compare file size.
This was a realistic original landscape drawing, with gradiants, tones, lots of details.
The file size for the versions with a few flat areas of color was much smaller than other versions (but less interesting, of course).
Gradiants that relied on an algorhthm to change color did not increase file size as much as the grandiants that I drew in by hand, meaning that each pixel was red as opposed to a formula for change.
The amount of detail (number of filled shapes, number of different lines) affected file size, and to the extent that a new shape requires a color different from the surrounding area, then number of colors affects file size.
The variation for the 450X 275 pixel area was 28K to 65K, for GIF files. The 28K images was very flat, few gradiants. The 65K gif included shadows, gradiants, and a pointillist technique in some areas. The final versions was about 40K, and represents a comprimise.
Anna Martin