Web Design in a Nutshell

Converting to the Web Palette

Regardless of the tools you use to create web graphics, when you convert to Indexed Color there are a number of issues to keep in mind that should guide the decisions you make along the way. This section takes a look at some of those decisions, particularly regarding the use of the Web Palette. Individual tools and their features will be discussed in the section Section 17.6.

Selecting a Palette

The first thing you should decide is which palette to apply to the image. Standard palette choices were defined earlier in this chapter. Your palette choice should be appropriate to the image. Use Adaptive (or ImageReady’s Perceptual) when the image contains photographic material or lots of blends and gradients in the graphic. If you’ve created your graphic using web-safe colors and you want to be certain they stay that way, or if you just want the image to look the same for all users, choose the Web Palette.

Reducing the Number of Colors

As stated throughout this book, it is always important to keep graphic file sizes as small as possible for web delivery. One way to reduce the file size is to reduce the number of colors the graphic contains. When you convert to the Web Palette, the Color Table for the graphic will contain all 216 colors, even if just a few of them actually appear in the image. Stripping away the unused colors can reduce file size significantly (depending on the image) without altering the appearance of the image. Specific techniques for ...