The majority of the usages in this book should be self-explanatory. The combination Filter ▸ Sharpening ▸ Unsharp Mask, for example, represents the menu sequence Filter followed by Sharpening and the menu item Unsharp Mask. Keystroke combinations are designated using the notation. The hyphen means both keys should be pressed simultaneously. Menu entries and action buttons are written using the File or OK typefaces, and list elements to be selected and new terms are written in italics.

Windows key:	Mac OS X key:
represents the Shift key.
represents the Enter key.
indicates a press of the Windows
or the Mac OS key.

The Windows and Mac OS X versions of the programs referenced in this book almost always use the same keystroke combinations, although the Windows key is replaced by the (option)^[3] key in the Mac OS. The Windows key is replaced by the key in the Mac.^[4] means shift in both systems ( represents a capital A). represents the return or enter key. The combination signifies use of in the case of a PC, and for a Mac. The same logic applies to the notation.

We will occasionally mention functions that require a right click to activate a context menu. Macintosh users who use a single-button mouse need to hold down the key and left click once to simulate a right click of a multi-button mouse. We recommend that Mac users invest in a two- or three-button mouse with a scroll wheel. This (not necessarily large) investment will help you a great deal when using this book.

We have cropped some of the screenshots in order to keep them down to a manageable size, and we have reduced the use of whitespace in some places to keep things clear.

The numbers in square brackets (e.g., [2]) refer to information listed in Appendix A.