Message-Id: <mailto:199409132244.RAA24115@library.wustl.edu> Date: Tue, 13 Sep 1994 09:02:37 -0500 From: Nick Cahill <mailto:ndcahill@FACSTAFF.WISC.EDU> Subject: Re: 8-bit vs. 24-bit color To: Multiple recipients of list IMAGELIB <mailto:IMAGELIB@ARIZVM1.BITNET>
>8-bit vs. 24-bit color.
>
>I have a garden-variety Dell comuter with a 17" monitor and graphics card
>capable of displaying 24-bit color. I delight in displaying an 8-bit color
>and a 24-bit color version of the same image side by side and having the
>viewer tell the difference. (I did this at a conference and most people
>guessed it wrong.)
>
>Of course there is a difference, and if you get up close and look at areas
>of slowly changing color (sky is a good example) you can see the difference.
>But, for everyday use at normal viewing distances, the factor of 3 savings in
>size is worth while.
> Walt
>
>Walter Gilbert, Asst. Dir. mailto:Walter_Gilbert@umail.umd.edu
>Computer Science Center Manager: Teaching Technologies
>University of Maryland at College Park 20742-2411 (301)405-6727
Although an 8-bit color file is only 1/3 the size of a 24-bit file, only 24-bit color images can be compressed using JPEG. A JPEG-compressed 24-bit file is considerably smaller than an 8-bit image -- by a factor of three to five. And it looks just as good if not better, IMHO. If file size is an issue (and when isn't it?) then I'd go with compressed 24-bit images every time.
Nick Cahill Dept. of Art History Univ. of Wisconsin-Madison