You can preview most digital images using Mac OS X's Preview application. Although you can't make many changes in the images you preview, you can get a quick view of images in various formats. Using Preview is simple.
Preview might or might not be the default application for viewing image files. If not, you can open any specific image file by first opening the application and using the Open command or by setting Preview to the application associated with a specific image file.
To learn how to associate files with an application, see "Determining the Application That Opens When You Open a Document," p. 169.
When you open an image in Preview, the image fills the screen by default. You can control the magnification of the image using the Preview's Display menu. You can also rotate the image if you need to.
One of the nice things that Preview does for you is enables you to convert an image from one format to another. You can do this using the Export command on the File menu. In the Export sheet, you can select the file format and the options for the format you choose.