Inside Photoshop® CS

The Lowdown on GIF

Surely by now you've been confronted with a choice: When you want to save to the Web, do you choose the GIF or JPEG file format? You won't find a lot of material written on the qualitative difference between the two formats, so this chapter is probably a really good place to unravel the mystery.

GIF: Indexed Color

As explained in Chapter 0, “Answers to the Most Important Imaging Questions,” the format of a GIF image is limited with respect to the number of colors it can hold, and as a result, the colors are palletized (indexed). They are indexed in a color table (which is stored in the header of the image file) for quick loading into, say, a Web page. GIF is not a new file format, and frankly, most of the interest in this file ...