Sử dụng photoshop cs5 part 29 doc

Using snapshots States are deleted from the History panel if any of the following occur: the specified maximum number of history states is exceeded; you clear or purge the panel; or the

Using snapshots

States are deleted from the History panel if any of

the following occur: the specified maximum number

of history states is exceeded; you clear or purge the

panel; or the panel is in linear mode, you click an

earlier state, and then resume editing the document

A snapshot, which is created from a history state,

remains on the panel even if any of the above occur

When you click a snapshot, the document is restored

to the state it represents Both snapshots and history

states are deleted when you close your document

In these instructions, you’ll choose snapshot

options, which affect all Photoshop files; on the

next page, you’ll learn how to create snapshots for

a specific document

To choose snapshot options:

1 Choose History Options from the History panel

menu The History Options dialog opens.A

2 Check or uncheck any of the following options

that pertain to snapshots:

Automatically Create First Snapshot to have

Photoshop create a snapshot every time a file is

opened (this option is checked by default and we

keep it on)

Auto matically Create New Snapshot When

Saving to have Photoshop create a snapshot

every time a file is saved The snapshot will be

named by the time of day it was created

Show New Snapshot Dialog by Default to have

the New Snapshot dialog appear whenever you

click the New Snapshot button, enabling you to

choose options

3 Click OK

A The History Options dialog contains three snapshot options.

If the Automatically Create New Snapshot When

Saving option is turned off for your History panel,

you should get in the habit of creating snapshots

periodically as you work and before running any

actions on your document If you use the New

Snapshot dialog (the second method below), you’ll

be able to choose whether the snapshot is made from

all the layers in the document, from all the layers at

a particular state, or from just the current layer

To create a snapshot of a state:

Method 1 (without choosing options)

1 Edit your document so it contains the changes

that you want to capture as a snapshot

2. If the Show New Snapshot Dialog by Default

option is off in the History Options dialog, click

the New Snapshot button. If that option is

on, Alt-click/Option-click the New Snapshot

button A new snapshot thumbnail appears

below the last one, in the upper section of the

panel

Method 2 (choosing options)

1 On the History panel, right-click the state that

you want to create a snapshot of and choose

New Snapshot AThe layer associated with that

history state becomes selected and the New

Snapshot dialog opens.B

2 Type a Name for the snapshot

3 Choose an option from the From menu:

Full Document to include in the snapshot all

the layers the document contained at the chosen

state

Merged Layers to merge into the Background all

the layers that were visible at the chosen state

Current Layer to create a snapshot of the layer

that became selected when you right-clicked a

history state

4 Click OK C

➤ To rename a snapshot, double-click the existing

name

A Right-click a state and choose New Snapshot from the context menu

B In the New Snapshot dialog, enter a name and choose which part of the image you want the snapshot to be created from

C A thumbnail for the new snapshot appears on the History panel.

Having snapshots on your History panel not only

adds flexibility to your workflow by letting you keep

document stages in reserve — it can save the day if,

say, a state that you were hoping to revert a

docu-ment to becomes deleted from the History panel

To make a snapshot become the current

state:

Do either of the following:

Click a snapshot name or thumbnail If the

History panel is in linear mode (as we

recom-mend), the document will revert to the

snap-shot stage of editing, and all the states will be

dimmed If you now resume editing, all the

dimmed states will be deleted

Alt-click/Option-click a snapshot name or

thumbnail to keep earlier states available and

have that snapshot become the latest state Use

this approach if you need to preserve access to

prior edits

➤ To delete a snapshot, drag it to the Delete

Current State button Remember that all

snap-shots disappear from the panel when a document

is closed anyway

Creating documents from states

By using the New Document command, you can spin

off versions of your current document (and the state

of the Layers panel) from any state or snapshot

To create a new document from a history

state or snapshot:

Do either of the following:

Right-click a snapshot or a state, then choose

New Document from the context menu A

Click a snapshot or a state, then click the New

Document from Current State button.

A new document appears onscreen, bearing the

title of the snapshot or state from which it was

created The starting state for the new document

will be named “Duplicate State.” BSave the new

document

A Right-click a snapshot or state and choose New Document

B This is the History panel for the new document.

Using the History Brush tool

When you apply strokes to a document with the

History Brush tool, pixels below the pointer are

restored from whichever state or snapshot you have

designated as the history source

Note: The History Brush tool can’t be used if

certain kinds of edits were made after the

docu-ment was opened, such as cropping, changing the

document color mode or canvas size, or adding or

deleting layers Furthermore, the tool can’t restore

deleted or modified layer effects, vector data (type or

shapes), pixels from a deleted layer, or the effects of

an adjustment layer Moral: Keep the layers in your

document for as long as possible!

To use the History Brush tool:

1 Open an image, and make some edits (For the

image shown at right, we duplicated an image

layer via Ctrl-J/Cmd-J, renamed the duplicate,

and applied a filter to it.) A–C

2 Choose the History Brush tool (Y or Shift-Y)

3 On the Options bar:

Click the Brush Preset picker arrowhead, then

click a brush on the picker

Choose a blending Mode, Opacity percentage,

and Flow percentage

4 On the History panel, click in the leftmost

column for a state or for a snapshot that was

created with the Full Document option, to

desig-nate it as the source for the History Brush tool

The history source icon moves to that slot.D

5 On the Layers panel, click the layer that you

want to restore pixels to, and make sure the

Lock Transparent Pixels button is deactivated

A This is the original image.

C This is how the image looks after we applied the

Charcoal filter to a duplicate image layer.

D Next, to set the history source icon, we clicked in the leftmost column for a state prior to “Filter Gallery,” but after the layer addition (in this case, at a state called

“Layer Via Copy”).

B We duplicated the image layer, then applied the Charcoal filter to the duplicate layer.

6 Apply strokes to the image Pixel data from the

prior state of that layer will replace the current

data where you apply strokes.A–C

➤ Say you apply some brush strokes to a layer (and

your History panel is in linear mode), then decide

a few editing steps later that you want to remove

them If you click the state above the one labeled

“Brush Tool” and then resume editing, the states

that you want to keep will be deleted from the

panel Instead, set the source for the History

Brush tool to the state above “Brush Tool,” click

the layer on the Layers panel that you applied the

brush strokes to, then with the History Brush

tool, paint out the strokes from the document

(This will make more sense when you actually

do it.)

C Some of the original color is visible in this final image.

A On the duplicate layer that we applied the filter to,

we applied strokes with the History Brush tool (the tool Opacity was 55%, and we used a big, scratchy-looking Spatter brush).

B In the Layers panel for the final image (which is shown below), you can see that we restored the original color to some areas of the duplicate layer.

Filling an area with a history state

or snapshot

The Fill command, when used with the History

option, fills a layer or selection with pixels from a

designated history state or snapshot Our Note on

page 182 also applies to this command

To fill a selection or layer with a history

state or snapshot:

1 Edit your document, and click an image layer A

2 Optional: Create a selection You can either leave

the selection edges sharp or use the Refine Edge

dialog to feather them.B

3 On the History panel, click in the leftmost

column for the state or snapshot to be used

as the fill data The history source icon will

appear where you click

4 Choose Edit > Fill (Shift-Backspace/Shift-Delete)

5. In the Fill dialog, do the following:

Choose Use: History C

Choose a Blending Mode and an Opacity

percentage

Check Preserve Transparency to replace only

existing pixels, or leave it unchecked to allow

pixels to appear anywhere on the current layer

This option is available only if the current layer

contains transparent pixels

Click OK.D

A This is the original image.

B We applied the Conté Crayon filter to a duplicate image layer, selected the bottom part of that layer, then feathered the selection via the Refine Edge command.

D The selection filled with the unedited imagery at an Opacity of 75%.

C In the Fill dialog, we chose Use: History.