Photoshop® CS4 All-in-One For Dummies®

Chapter 1. Specifying Size and Resolution

In This Chapter

• Comparing pixel and vector images

• Understanding how pixels appear on different monitors

• Working with the Image Size command

• Resampling images (if you must)

• Adjusting the canvas size

• Cropping an image

Size and resolution are slippery subjects. A digital image's size may refer to its file size, how big you want it to be on a printed page (such as 3 × 5 or 8 × 10 inches), the size you want it be on-screen (full screen or just part of the screen), or how densely packed the pixels are (its resolution). To use Photoshop's tools so that an image looks good in print or on-screen, you need to know not only what type of size you're working with, but also what the image's resolution is — and how both of these factors might affect the image's appearance.

Given all the factors in size and resolution, it's not surprising that Photoshop has evolved into a Swiss Army knife. It offers multiple tools for specifying, viewing, or changing an image's size. In this chapter, I give you a bit of background in both size and resolution so that you know what tools to use and how to use them. In Book IX, you can find out how to use the basics I cover here in order to tailor size and resolution specifically for print.

I also explain how to change image size without harming your image. Yes, you can harm your image. Not intentionally, of course. But it can happen ...