Photoshop® CS4 Bible

15.1. Preparing to Work with Color

You may be wondering how all this is going to work, considering this is mostly a black-and-white book. Many examples include objects with known colors, and the color numbers that are appropriate for those objects will be discussed. More importantly, there will be color versions of many of the examples in the color section of this book and on the book's CD.

Before you start working on the colors in an image, there are some important things to do, as discussed in the following sections.

15.1.1. Check the image size and resolution

It is critical to check the image size and resolution to make sure it is sufficient for the image's purpose. You wouldn't want to do a lot of color work only to find out at the end of the process that your image is too small for its purpose. Usually, 300 ppi at the final size in inches is plenty for images destined for print; 72 ppi at the final size in pixels is plenty for images destined for the Web.

When you select an image's size in the Image Size dialog box (choose ImageImage Size), the key is to deselect the Resample button in the Image Size dialog box before you increase any numbers in the box (size or resolution numbers). Then you can type in the higher numbers and the dialog box shows you the other size or resolution numbers that the image can have in order to reproduce it at a high quality.

If you need to decrease ...