Masks and Channels Digital Imaging

Masks  Let you isolate and protect parts of an image  Based on a selection The area not selected is masked or protected from editing  Helpful to use because you can create a selection to save time if you want to re- use it later Also effective with color changes and filter effects

Quick Masks  These are temporary masks, they are helpful when trying to make a selection of a difficult shape / image  This converts a selection border into a temporary mask  It is discarded once it is converted to a selection It is not saved unless you make it a permanent selection

When in Quick Mask mode  A red overlay appears to mask and protect an area outside of the selection  You can only apply changes to the unprotected area that is visible and selected  PS defaults to Grayscale mode the foreground color defaults to black and the background color defaults to white

When in Quick Mask mode  Painting with white erases the mask and increases the selected area  Painting with black adds to the mask and decreases the selected area

On the toolbar is where the QUICK MASK icon is located. Puts you into Quick MASK MODE Puts you into STANDARD MODE

Permanent Masks  Stored on the Channel palette (next to the layers tab on the Layers palette)  Get stored as a grayscale channel called alpha channel

Channels  PS uses channels to store an image’s color information and information about spot color  Channels do not print

Alpha channels  A storage area for information  Use to create a more permanent mask by storing it and editing it  Saved on the channels palette  Can be added or deleted  Can be edited using painting or editing tools

The Extract Command  Provides a sophisticated way to isolate a foreground object from its background  Objects with wispy, intricate or indefinable edges can be clipped from their background with a minimum amount of work

Where to find the Extract command Filter > Extract