Understanding color depth

Color depth, also called bit depth, refers to the number of colors each pixel in an image can display. As the color depth increases, the number of colors an image can display increases. Each pixel’s color information is stored in a certain number of computer bits — from 1 bit to 24 bits. In a 1-bit image, each pixel can display only one of two colors — black or white. In a 24-bit image, each pixel can display one of 16 million colors. Images with a color depth of 16 million colors work well with color photos because they contain the most colors, but they also require the most memory.

In Corel Paint Shop Pro, you can use the following color depths:

• 2 color (1-bit)
• 16 color (4-bit),
• grayscale (8-bit)
• 256 color (8-bit)
• 16 million color (24-bit)

Before you change the color depth of your image, consider the following:

• Many effect and correction commands work on 16 million-color images only. Therefore, it is best to create most images using 16 million-colors. After you finish working on an image, you can decrease its color depth and save it in another format.
• Computer monitors also have a color depth that is determined by the monitor’s capabilities as well as the selected color setting. If you display an image with a higher color depth than the monitor can display, the image has some color distortion.
• Some file formats limit the number of supported colors so that images display correctly on a variety of monitor types. For example, GIF images, a popular format for the Web, contain up to 256 colors (8-bit depth).