Photoshop® CS5 Bible

Chapter 3. Image Basics

IN THIS CHAPTER

• Understanding the file formats that Photoshop supports for images, video, and 3D objects

• Knowing the difference between raster and vector images

• Opening an image in another format

• Understanding the resizing algorithms

• Creating a border around an image

• Cropping and straightening images

• Removing a border from an image

Photoshop's purpose is editing image files that have come from a variety of sources. Photoshop supports a large number of file formats. The different file formats can be confusing, so this chapter spends a bit of time talking about each of the different file formats to help you understand some of the benefits and drawbacks of each one.

In this chapter, you also learn some other important concepts about file size and resolution. Understanding the relationship among the file size, the resolution, and the ultimate destination of the file helps you know what size and resolution to use for an image. You also learn the different types of algorithms that Photoshop uses to resample images when changing the size. Understanding the algorithms helps you know which ones to use to get the best results when resizing images.

This chapter also discusses how and why to crop images. You learn how to use several tools in Photoshop to quickly and accurately crop, trim, rotate, and straighten images.

Exploring File Types

If you have worked with images long enough, you have probably come across a variety of file formats. Although having just one file format would ...