Читать книгу Adobe Creative Cloud All-in-One For Dummies - Christopher Smith - Страница 104

Typically you don’t edit your images in the Index color mode, but you probably have saved a file in this mode. If you have ever saved a GIF file out of Photoshop, you have experienced working with Indexed color firsthand. Indexed Color mode (see Figure 2-7) uses a color lookup table (CLUT) to create the image from a limited palette of colors. In this example, the flower was set to reduce to 10 colors.

FIGURE 2-7: Index color uses a limited number of colors to create an image.

A CLUT contains all colors that make up an image, like a box of crayons used to create artwork. If you have a box of only eight crayons that are used to color an image, you have a CLUT of only eight colors. Of course, your image would look much better if you used the 64-count box of crayons with the sharpener on the back, but those additional colors also increase the size of the CLUT and the file size.

The highest number of colors that can be in Indexed Color mode is 256. When saving web images, you often have to define a color table in order to keep a file size small. We discuss saving files for the web in Chapter 10 of this minibook.

If your image is not in Indexed color, choose Image⇒ Mode⇒ Indexed Color, then, choose Image ⇒ Mode ⇒ Color Table to see the color table making up an image.