Operation Manual
Working with Graphics, Animation, and Multimedia 53
For your convenience, WebPlus includes two swatch panels
incorporating the Web-safe colors. (Look for
WEBSAFE1.GIF and
WEBSAFE2.GIF in the /WP80/SAMPLES folder.) You can paste either
one into your paint program’s “canvas” area and pick colors from it
using the program’s eye dropper tool. Or you can load the supplied
WEBSAFE.PAL palette so it’s used in the color selection table. It’s
especially important when anti-aliasing graphics to ensure that the edge
colors the program applies come from the safe palette.
As a rule, if you’re concerned with 256-color display, save low-color
bitmap images created in your paint program in the .GIF format using
the safe palette. Avoid using a unique palette per image; if you have
multiple GIFs per Web page, different palettes may clash and all
images will suffer.
Performance
“Performance” may seem like an odd aspect of graphic design, but it’s
actually one of the key factors in how users will judge your Web site.
Technically, performance means load time: how long it takes for your
whole page, including text and graphics, to display completely in a
Web browser. In practice, it’s hard to measure, and subjective factors
intrude. Connection bandwidth, server speed, and modem rating all
play a part. As discussed earlier, it’s always wise to design the safe area
of each page to give visitors something to look at, read, and/or think
about, and thus offset the perception of delay while the rest of the page
loads.
Load time is a function of the total size of all the page objects that need
to load; and graphics usually take up the lion’s share. That’s why we
can talk about the “performance” of your page as a function of the total
file size of its graphics.
Asaruleofthumb,use 60K bytes per page as a maximum.Assuming
that the average home user’s dial-up modem can download 3-5K bytes
per second, that’s a load time of 12 to 20 seconds. Any longer than that
is asking for trouble.
You can determine the actual size of your files by publishing one
page at a time to a local folder (using File/Publish Site/to Disk
Folder...), then using Windows Explorer to examine the contents
of the folder. View the files by date and Shift-select the most
recent batch, then right-click and choose Properties to see the
aggregate byte count. Obviously, the lower the better.