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