In fact, it's even possible to convert the Eraser tool 6 What You’ll Do Set History Panel Options Work with Linear and Non-Linear History Control the Creative Process with Snapshots Dupl
Trang 1Working with the History
Panel
Introduction
Adobe introduced the History panel in Photoshop 5, and the
graphic design world hasn't been the same since On an
ele-mentary level, the History panel gives you the ability to
per-form multiple undos Think of History as a magical mistake
correction tool that never wears out However, the History
panel does much more than give you the ability to go back in
time and correct your mistakes The History panel is simply a
tool, but when you combine the power of the History panel
with the History brush and the Art History brush, you have a
trio of tools that can take your creative designs to the next
level and beyond
Adobe Photoshop gives you two ways to use the History
panel—linear and non-linear The linear mode helps you keep
track of your recent steps, and erases any steps that interfere
with a linear flow to the panel The non-linear mode
pre-serves all the steps (linear or non-linear), and is useful when
you need to think outside the linear box
Photoshop raises the bar with the History panel by giving
you the ability to record and save the commands performed
to a document in a text file Now, you can finally know
exactly what you did to an image And since the document
can be printed, you can create History text documents of
your favorite restoration and manipulation techniques, and
save them
In addition, when you combine the History brush with the
History panel, you have an awesome creative tool that can't
be beat In fact, it's even possible to convert the Eraser tool
6
What You’ll Do
Set History Panel Options Work with Linear and Non-Linear History Control the Creative Process with Snapshots
Duplicate a History State in Another Document
Save the History State of a Document Review the History State Text File Combine the History Brush with a History State
Use the Art History Brush Change the Eraser Tool into the History Brush
Control History States
Trang 2Working with the History panel requires a firm understanding of how the panel functions, and what you can and cannot do with History The History panel records your steps as you work through a document A step is defined as a specific action, such as creating a layer or adding
a brush stroke Every time you perform an action, a step is recorded in the History panel The History panel gives you the ability to go back to a previous history state, which is the same as performing an undo com-mand You can perform multiple undo commands up to the number you set in Photoshop preferences for the History States In addition, the
History panel creates snapshots of the document Snapshots are
images of the current state of the document Snapshots are used in conjunction with the History and Art History Brushes to create special effects
Setting History
Panel Options
Set Number of History States
Click the Edit (Win), or Photoshop
(Mac) menu, point to Preferences,
and then click Performance.
Enter a value from 0 to 1000 for the
number of steps recorded in the
History States box
Click OK.
3
2
Did You Know?
You can duplicate a History State.
Hold down the Alt (Win) or Option
(Mac) key, and then click the History
State you want to duplicate
You can use keyboard shortcuts to
perform multiple undos The History
panel represents the ability to perform
multiple undo commands However,
when you press Ctrl+Z (Win), or A+ Z
(Mac) you only move back and forth
between the last two commands, just
like a normal undo To perform multiple
undo commands, press Ctrl+Shift+Z
(Win) or A+Shift+Z (Mac) to move
forward through all your History steps,
or press Alt+Shift+Z (Win) or
Option+Shift+Z (Mac) to move
Trang 3Set History Options
Select the History panel.
Click the History Options button,
and then click History Options.
Select the check boxes for the
History Options you want to use:
◆ Automatically Create First
Snapshot Creates a snapshot
(image) when the document
first opens
◆ Automatically Create New
Snapshot When Saving
Creates a snapshot every time
you save the document
This is useful for keeping track
of the changes made to a
document
◆ Allow Non-Linear History.
Allows you to operate History in
a non-linear state
◆ Show New Snapshot Dialog By
Default Opens a dialog box
with options each time you
create a new snapshot
◆ Make Layer Visibility Changes
Undoable Instructs Photoshop
to make any changes made to a
layer's visibility undoable
Click OK.
4
3
2
1
3
4 2 1
Trang 4The History panel records each step performed on a Photoshop docu-ment in a linear fashion from top to bottom However, the purpose of the History panel is not to simply record your progress through a docu-ment; it's there to help you make changes and go back in time to cor-rect mistakes Photoshop gives you two History panel modes—linear and non-linear When you work in a linear History panel, clicking on a previous step causes all steps underneath to become grayed out (unavailable) If you then add a step, the grayed-out steps are removed and the new step is added to the bottom of the list A linear panel is organized and very RAM efficient; however, once a History Step is removed, it cannot be retrieved When you work in a non-linear History panel, clicking on a previous step does not cause the steps underneath
to become grayed out If you then add a step, the new step is added to the bottom of the History panel The new step represents the charac-teristics of the step you selected, plus any added actions A non-linear panel is not organized and consumes more RAM Its advantage lies in the fact that History steps are not deleted, they are simply reorganized
Working with Linear
and Non-Linear
History
Work with Linear History
Select the History panel.
Click the History Options button,
and then click History Options.
Clear the Allow Non-Linear
History check box, and then click
OK.
Work in the document until you
have generated 10 or 15 steps in
the History panel
Move halfway up the History
panel, and then click on a step
The steps below the selected step
turn gray
Perform another action to the
image
The grayed steps are removed,
replaced by the latest action
applied to the image
6
5
4
3
2
4 1
Trang 5Work with Non-Linear History
Select the History panel.
Click the History Options button,
and then click History Options.
Select the Allow Non-Linear
History check box.
Click OK.
Work in the document until you
have generated 10 or 15 steps in
the History panel
Move halfway up the History
panel, and then click on a step
The steps below the selected step
do not change
Perform another action to the
image
The new step is added to the
bottom of the History steps
7
6
5
4
3
2
7
2
5 1
Did You Know?
You can quickly purge the History
States, and therefore recoup
addi-tional RAM Hold down the Alt (Win) or
Option (Mac) key, click the History
Options button, and then click Clear
History But be warned; there is no
undo available You are stuck with your
decision
You can reduce memory usage by
using linear history Non-linear History
requires more RAM to maintain If you
don’t require a non-linear history and
want to decrease RAM usage, then
you can turn it off In the History panel,
click the History Options button, click
History Options, clear the Allow
Non-Linear History check box, and then
click OK
4
3
Trang 6The History panel contains more than just steps; it also holds Snapshots A Snapshot is an image of the document as it exists at the time the snapshot was taken The History panel can hold as many snapshots as needed, and they are not subject to the number of History States you chose in Preferences That means they stay with the docu-ment throughout the creative process By default, Photoshop takes a snapshot of the image when it first opens This snapshot represents the original state of the image, before any adjustments or modifications are applied, and is identified with the file name of the image It's a good idea to create a snapshot every time you make a major change to the image That way, if you want to start all over, all you have to do is click
on the snapshot, and Photoshop returns you to the moment in time in which the snapshot was created It's like having your own personal time machine
Controlling the
Creative Process
with Snapshots
Create Snapshots
Select the History panel.
Click the History Options button,
and then click History Options.
Select the Show New Snapshot
Dialog by Default check box, and
then click OK.
Perform several actions to the
image
Click the Create New Snapshot
button
Type a name for the new snapshot
Click the From list arrow, and then
click a save image information
option:
◆ Full Document Saves the
entire visible image and all
layers
◆ Merged Layers Saves only the
merged layers
◆ Current Layer Saves only the
active layer
Click OK.
8
7
6
5
4
3
2
1
2
6
7
5
8 1
Trang 7Here's a tool to help you gain control over the creative process, and save you a lot of time and effort as well The History panel lets you create new documents based on a specific History step or snapshot
For example, you're working on a complicated image, and you want to isolate a portion of the image in another document This will not only help you reduce the clutter, but working on a portion of the image in a separate document creates a document with a much smaller file size, and that will help Photoshop work faster
Duplicating a History
State in Another
Document
Create Another Document
Select the History panel.
Click on the snapshot or History
State you want to use for the new
document
Click the Create New Document
From Current State button.
Photoshop creates a new
document based on the selected
snapshot or state The new
document's History panel contains
one snapshot or one state
IMPORTANT Snapshots are
not saved with the Photoshop
document When you reopen a
document, the History panel will
display one snapshot of the
current state of the image or one
History state
3
2
1
2
3 1
New document based on the selected snapshot or state
Did You Know?
You can save RAM by using the
History panel When you create a new
document using the History panel, it’s
very RAM efficient, as opposed to the
traditional copy and paste method