Photoshop 6 for Windows Bible- P12 ppt

✦ Working with non-sequential states: If you don’t like the idea of losing your undone states — every state is sacred, after all — choose the History Optionscommand and select the Allow

✦ Changing the number of undos: By default, Photoshop records the last 20

operations in the History palette When you perform the 21st operation, thefirst state is shoved off the list

In Photoshop 6, you set the number of operations that the History palettetracks in the Preferences dialog box Choose Edit ➪ Preferences ➪ General orpress Ctrl+K to open the dialog box and enter the value you want to use in theHistory States box If your computer is equipped with 32MB or less of RAM, youmight want to lower the value to 5 or 10 to maintain greater efficiency On theother hand, if you become a time-traveling freak (like me) and have plenty ofRAM, turn it up, baby, all the way up!

✦ Undone states: When you revert to a state by clicking on it, every subsequent

state turns gray to show that it’s been undone You can redo a grayed statesimply by clicking on it But if you perform a new operation, all grayed statesdisappear You have one opportunity to bring them back by pressing Ctrl+Z; ifyou perform another new operation, the once-grayed states are gone for good

✦ Working with non-sequential states: If you don’t like the idea of losing your

undone states — every state is sacred, after all — choose the History Optionscommand and select the Allow Non-Linear History check box (see Figure 7-27)

Undone states no longer drop off the list when you perform a new operation

They remain available on the off chance that you might want to revisit them

It’s like having multiple possible time trails

Figure 7-27: Choose the History Options command to

permit Photoshop to record states out of order

The Allow Non-Linear History check box does not permit you to undo a singlestate without affecting the subsequent states For example, let’s say you paintwith the airbrush, smear with the smudge tool, and then clone with the rubberstamp You can revert back to the airbrush state and then apply other opera-tions without losing the option of restoring the smudge and clone But you can’tundo the smudge and leave the clone intact Operations can only occur in thesequence they were applied

Note

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If you revert back to a state and then apply an edit, the reverted state and allactions that fall between that state and the new edit are set off by horizontallines running across the palette The lines show you which operations you’lllose if you undo the first state in the group.

✦ Stepping through states: As I mentioned earlier, you can press -Ctrl+Alt+Z to

undo the active step or Ctrl+Shift+Z to redo the next step in the list Backsteppinggoes up the list of states in the History palette; forward stepping goes down Keep

in mind that if the Allow Non-Linear History check box is active, backsteppingmay take you to a state that was previously inactive

✦ Flying through states: Drag the right-pointing active state marker (labeled in

Figure 7-26) up and down the list to rewind and fast-forward, respectively,through time If the screen image doesn’t appear to change as you fly by cer-tain states, it most likely means those states involve small brushstrokes orchanges to selection outlines Otherwise, the changes are quite apparent

✦ Taking a snapshot: Every once in a while, a state comes along that’s so great,

you don’t want it to fall by the wayside 20 operations from now To set a stateaside, choose New Snapshot or click the little page icon at the bottom of theHistory palette

By default, Photoshop no longer displays the New Snapshot dialog box askingyou to name the snapshot If you want to name a snapshot, Alt-click the NewSnapshot icon Or choose History Options from the palette menu and selectthe Show New Snapshot Dialog by Default option Photoshop then presentsthe dialog box In the dialog box, you also can specify whether you want tosave all layers (as by default), flatten the image, or retain just the active layer

The new snapshot — as it’s called — then appears in the top portion of the

palette

If you turn on the Show New Snapshot Dialog by Default check box, you cancircumvent the dialog box by Alt-clicking the New Snapshot icon (The statehas to be active to convert it to a snapshot, so you can’t drag a state and drop

it onto the page icon, as you can drag-and-drop elements in other palettes.)Photoshop lets you store as many snapshots as your computer’s RAM permits.Also worth noting, the program automatically creates a snapshot of the image as

it appears when it’s first opened If you don’t like this opening snapshot, you canturn it off inside the History Options dialog box

✦ Creating a snapshot upon saving the image: Select the Automatically Create

New Snapshot When Saving box in the History Options dialog box to create anew snapshot every time you save your image

✦ Saving the state permanently: The problem with snapshots is that they last

only as long as the current session If you quit Photoshop or the programcrashes, you lose the entire history list, snapshots included To save a state soyou can refer to it several days from now, choose the New Document command

or click the leftmost icon at the bottom of the History palette You can also dragand drop a state onto the icon Either way, Photoshop duplicates the state to anew image window Then you can save the state to the format of your choice

the trash icon at the bottom of the palette Your image updates accordingly

If the Allow Non-Linear History check box is on, clicking the trash can deletesjust the active state

If your machine is equipped with little RAM or you’re working on a larly large image, Photoshop may slow down as the states accumulate If itgets too slow, you may want to purge the History palette You can clear everystate from the active state forward without affecting the image by Alt-clickingClear History in the palette menu You can also choose Edit ➪ Purge ➪Histories to purge the list of states for all open documents

particu-You can’t undo either purge command So if you want to clear the states fromthe palette but have the option of choosing Undo to bring them back, choose

Clear History without Alt-clicking.

Painting away the past

The History palette represents the regimental way to revert images inside Photoshop

You can retreat, march forward, proceed in linear or non-linear formation, capture

states, and retire them Every state plays backward in the same way it played

for-ward It’s precise, predictable, and positively by the book

But what if you want to get free-form? What if you want to brush away the present

and paint in the past? In that case, a palette isn’t going to do you any good What

you need is a pliable, emancipated, free-wheeling tool

As luck would have it, Photoshop offers five candidates — the eraser, magic eraser,

background eraser, history brush, and art history brush The eraser washes away

pixels to reveal underlying pixels or exposed canvas The magic eraser and

back-ground eraser, both added in Version 5.5, erase a range of similarly colored pixels

and background pixels, respectively The history brush takes you back to a kinder,

simpler state; the art history brush does the same but enables you to paint using

special artistic effects Although the functions of these tools overlap slightly, they

each have a very specific purpose, as becomes clear in the following sections

As you work with any of these tools, remember that you can use the Edit ➪ Fade

com-mand (formerly on the Filter menu) to blend the altered pixels with the originals, just

as you can when applying a filter You can adjust both the opacity and blend mode of

the erased or painted pixels Chapter 10 explores the Fade command in detail

Cross-Reference

Caution

Tip

The eraser tool

When you work with the eraser, you can select from four eraser styles: Paintbrush,Airbrush, Pencil, and Block Block is the old 16 × 16-pixel square eraser that’s greatfor hard-edged touch-ups The other options work exactly like the tools for whichthey’re named

In earlier versions of Photoshop, pressing E cycled you through the eraser styles Thatshortcut now cycles through the eraser, magic eraser, and background eraser, all ofwhich share a flyout menu and keyboard shortcut ( E) in Version 6 You now mustselect the eraser style from the Mode pop-up menu on the Options bar, as shown inFigure 7-28 (press Enter with the eraser selected in the toolbox to display the bar)

Figure 7-28: When the eraser is selected, the Mode pop-up menu

offers a choice of eraser styles rather than the brush modes available for the painting tools

In addition to four styles, the Options bar provides the Brush palette, the Opacitycontrol, and the Brush Dynamics palette, all of which work as described in Chap-ter 5 When the Paintbrush option is active, you even have access to the Wet Edgescheck box, also covered in Chapter 5 The only thing you can’t do is choose a brushmode (Normal, Overlay, Darken, Lighten, and so on) — although, as I mentioned alittle while ago, you can apply the Fade command after the fact to fade and blendyour eraser strokes

Although the eraser is pretty straightforward, there’s no sense in leaving any stoneunturned So here’s everything you ever wanted to know about the art of erasing:

✦ Erasing on a layer: When you’re working on the Background layer, the eraser

merely paints in the background color Big whoop What distinguishes theeraser tool from the other brushes is layers If you drag on a layer and dese-lect the Lock check boxes for transparency and image pixels in the Layerspalette, the eraser tool removes paint and exposes portions of the underlyingimage The eraser tool suddenly performs like a real eraser

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✦ Erasing lightly: Change the Opacity setting on the Options bar to make

por-tions of a layer translucent in inverse proportion to the Opacity value Forexample, if you set the Opacity to 90 percent, you remove 90 percent of theopacity from the layer and, therefore, leave 10 percent of the opacity behind

The result is a nearly transparent stroke through the layer

✦ Erasing versus using layer masks: As described in the “Creating layer-specific

masks” section of Chapter 12, you can also erase holes in a layer using a layermask But unlike the eraser — which eliminates pixels for good — a layer maskdoesn’t do any permanent damage On the other hand, using the eraser tooldoesn’t increase the size of your image as much as a layer mask does (You can

argue that any operation — even a deletion — increases the size of the image in

RAM because the History palette has to track it But the eraser is still morememory-efficient than a layer mask.) So it’s a trade-off

✦ Erasing with the pencil: When you work with the pencil tool and select the

Auto Erase check box on the Options bar, you draw in the background colorany time you click or drag a pixel colored in the foreground color This tech-nique can be useful when you’re drawing a line against a plain background

Set the foreground color to the color of the line; set the background color tothe color of the background Then use the pencil tool to draw and erase theline until you get it just right I use this feature all the time when preparingscreen shots Adobe engineers call the Auto Erase check box their “ode toFatbits,” from the ancient MacPaint zoom function

Like the eraser, the pencil tool is affected by the Lock check boxes in theLayers palette Unlike the eraser, the pencil always draws either in the fore-ground or background color, even when used on a layer

✦ Erasing to history: Press Alt as you drag with the eraser to paint with the

source state identified by the history brush icon in the History palette (Bydefault, Photoshop sets the source state to the image as it appeared whenfirst opened.) It’s like scraping away the paint laid down by the operations fol-lowing the source state, as demonstrated quite graphically in Figure 7-29

Note

Figure 7-29: After making a dreadful mistake (left), I Alt-dragged

with the eraser tool to restore the image to the way it looked in the source state (right)

Alternatively, you can select the Erase to History check box on the Optionsbar In this case, dragging with the eraser reverts and Alt-dragging paints inthe background color

Many people use the term “magic eraser” to refer to the eraser set in revertmode But Photoshop 5.5 introduced an official magic eraser, which erasesbackground pixels instead of erasing to history So be careful not to get thetwo confused

The magic eraser

As I just mentioned, the magic eraser, found on the same flyout as the regulareraser, erases background pixels Or, at least, that’s the idea When used incor-rectly, the magic eraser wipes out any pixels that it touches

If you’re familiar with the magic wand, which I cover in Chapter 8, using the magiceraser is a cinch The two tools operate virtually identically, except that the wandselects and the magic eraser erases

When you click a pixel with the magic eraser, Photoshop identifies a range of larly colored pixels, just as it does with the magic wand But instead of selecting thepixels, the magic eraser makes them transparent, as demonstrated in Figure 7-30.Bear in mind that in Photoshop, transparency requires a separate layer So if theimage is flat (without layers), Photoshop automatically floats the image to a sepa-rate layer with nothing underneath Hence the checkerboard pattern shown in thesecond example in the figure — transparency with nothing underneath

simi-Note

Figure 7-30: To delete a homogeneously colored background, such

as the sky in this picture, click inside it with the magic eraser (bottom)

The Lock check boxes in the Layers palette affect the magic eraser When you have

no check boxes selected, the magic eraser works as I just described it But if you

lock transparent pixels, the magic eraser paints opaque pixels in the background

color and leaves transparent areas untouched You can’t use the magic eraser at

all on a layer for which you’ve locked image pixels

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You can further alter the performance of the magic eraser through the controls onthe Options bar, as described in the following list Except for the Opacity value,these options work the same way for both the magic eraser and magic wand:

✦ Opacity: Lower this value to make the erased pixels translucent instead of

transparent Low values result in more subtle effects than high ones

✦ Use All Layers: When turned on, this check box tells Photoshop to factor in

all visible layers when erasing pixels The tool continues to erase pixels onthe active layer only, but it erases them according to colors found across alllayers

✦ Anti-aliased: To create a soft fringe around the outline of your transparent

area, leave this option turned on If you’d prefer a hard edge — as when using

a very low Tolerance value, for example — turn this check box off

✦ Contiguous: Select this final check box, and the magic eraser deletes

contigu-ous colors only — that is, similar colors that touch each other If you prefer to

delete all pixels of a certain color — such as the blue pixels in Figure 7-30 thatare divided from the rest of the sky by the lion — turn the Contiguous checkbox off

The more magical background eraser

The magic eraser is as simple to use as a hammer, and every bit as indelicate Itpounds away pixels, but it leaves lots of color fringes and shredded edges in itswake You might as well select an area with the magic wand and press Backspace.The effect is the same

The more capable, more scrupulous tool is the background eraser As strated in Figure 7-31, the background eraser deletes background pixels as you dragover them (Again, if the image is flat, Photoshop floats the image to a new layer toaccommodate the transparency.) The tool is intelligent enough to erase backgroundpixels and retain foreground pixels provided that — and here’s the clincher — youkeep the cross in the center of the eraser cursor squarely centered on a back-ground-color pixel Move the cross over a foreground pixel, and the backgrounderaser deletes foreground pixels as well As Figure 7-32 demonstrates, it’s the posi-tion of the cross that counts

demon-As is the case when you work with the magic eraser, the Lock check boxes in theLayers palette affect the background eraser In this case, locking image pixels pre-vents you from using the background eraser Be aware that if you drag over a selec-tion that’s already partially transparent, locking transparent pixels does not protectthe selection from the background eraser

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Figure 7-31: Drag around the edge of an image with the background

eraser to erase the background but leave the foreground intact

You can select a brush for the background eraser in the Brush drop-down palette

on the Options bar In Photoshop 6, you can press the arrow keys to move from one

brush icon to another in the palette Pressing the bracket keys, [ and ], lowers and

raises the brush size — by 10 pixels for brushes smaller than 100 pixels in diameter,

by 25 pixels for brushes from 100 pixels to 199 pixels in diameter, and by 50 pixels

for brushes 200 pixels and larger If you simply want to switch from a hard brush to

a soft one, press Shift-left bracket; press Shift-right bracket to go from a soft brush

to a hard one

You can also modify the performance of the background eraser using the Options

bar controls, pictured in Figure 7-33 These options are a bit intimidating at first,

but they’re actually pretty easy to use:

✦ Limits: Choose Contiguous from this pop-up menu, and the background eraser

deletes colors inside the cursor as long as they are contiguous with the colorimmediately under the cross To erase all similarly colored pixels, whethercontiguous or not, select Discontiguous One additional option, Find Edges,searches for edges as you brush and emphasizes them Although interesting,Find Edges has a habit of producing halos and is rarely useful

✦ Tolerance: Raise the Tolerance value to erase more colors at a time; lower

the value to erase fewer colors Low Tolerance values are useful for erasingaround tight and delicate details, such as hair

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Figure 7-32: Keep the cross of the background eraser cursor over

the background you want to erase (top) If you inadvertently move the cross over the foreground, the foreground gets erased (bottom)

Figure 7-33: The seemingly intimidating background eraser options are actually

pretty intuitive

✦ Protect Foreground Color: Select this check box to prevent the current

fore-ground color (by default, black) from ever being erased Stupid, really, butthere it is

✦ Sampling: This pop-up menu determines how the background eraser

deter-mines what it should and should not erase The default setting, Continuous,tells the erasers to continuously reappraise which colors should be erased asyou drag If the background is pretty homogenous, you might prefer to use theOnce option, which samples the background color when you first click anderases only that color throughout the drag Select Background Swatch toerase only the current background color (by default, white)

Like other brush-oriented tools, the background eraser responds to the settings in

the Brush Dynamics palette, also shown in Figure 7-33 Select Fade from the pop-up

menus to taper your eraser strokes as you drag If you set the Tolerance pop-up to

Fade, the tool becomes more and more sensitive as you drag The values that you

enter in the adjacent options boxes control how quickly the Size or Tolerance

val-ues fade If you own a pressure-sensitive tablet, such as the Pen Partner or Intuos

from Wacom, select Stylus to adjust the size or tolerance according to pen pressure

Chapter 5 covers the Brush Dynamics palette, as well as all things brush-oriented,

including creating and managing brush presets

The history brush

Painting with the history brush tool gives you results similar to Option-dragging

with the eraser (or selecting the eraser’s Erase to History option) Just drag with

the history brush to paint down to the source state targeted in the History palette

You also can vary the opacity of your strokes with the Opacity setting on the

Options bar But the history brush offers two advantages over the eraser

First, you can take advantage of brush modes By choosing a different brush mode

from the Mode pop-up menu on the Options bar, you can mix pixels from the

changed and saved images to achieve interesting, and sometimes surprising,

effects Second, you don’t have to cycle through brush styles as with the eraser

tool Just select the history brush and start painting

Cross-Reference

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If you fell in love with the history brush in Version 5, you may be wondering what pened to the Impressionist mode, which enabled you to retrieve the source state andsmear it around to create a gooey, unfocused effect As of Version 5.5, that function, aswell as some other effects, come to you by way of the art history brush, discussed next.The two brushes share a flyout menu in the toolbox, as well as a keyboard shortcut, the

hap-Y key If you selected the Use Shift Key for Tool Switch option in the Preferences dialogbox, you toggle between the two tools by pressing Shift+Y Otherwise, pressing Y alonetoggles the tools

I advise you to get in the habit of using the history brush instead of using theeraser’s Erase to History function Granted, the eraser offers you four brush styles(paintbrush, pencil, airbrush, and block) But when weighed against brush modes,the brush styles aren’t much of an advantage All things considered, the historybrush is superior, and it doesn’t require you to press Alt or select a check box toswitch to history mode The history brush is also more intuitive because its iconmatches the source state icon in the History palette

As you play with the history brush, keep in mind that you don’t have to limit self to painting into the past Just as the History palette lets you skip back and forthalong the train track of time, the history brush lets you paint to any point in time.The following steps provide an example of how you can use the History palette toestablish an alternative reality and then follow up with the history brush to mergethat reality with the present It’s trippy stuff, I realize, but I’m confident that with alittle effort, you can give that post-modern brain of yours a half twist and wrap itaround these steps like a big, mushy Möbius strip

your-STEPS: Brushing to a Parallel Time Line

1 Open the image you want to warp into the fourth dimension I begin with a

map of Japan (Figure 7-34) Japan is a wacky combination of 17th-century tural uniformity, 1950’s innocence, and 21st-century corporate imperialism,

cul-so it strikes me as a perfect subject for my compound-time experiment

2 Apply a couple of filters I choose Filter ➪ Pixelate ➪ Mosaic and set the Cell

Size value to 20 pixels Then I apply Filter ➪ Stylize ➪ Emboss with a Height of

5 pixels and an Amount of 200 percent Figure 7-35 shows the results

3 Choose the History Options command from the History palette menu Then

turn on the Allow Non-Linear History check box and press Enter

4 Click the Open item in the History palette This reverts the image to the state

at which it existed when you first opened it But thanks to non-linear history,Photoshop retains the alternate filtered versions of the image just in caseyou’d like to revisit this timeline in the future

5 Click in front of the first filter effect in the History palette to make it the source state In my case, I click in front of the Mosaic item.

Tip

Note

Figure 7-34: This map of Japan comes from the Digital

Stock image library

Figure 7-35: The results of applying the Mosaic (left) and Emboss (right) filters.

Both effects are overstated, so I’ll undo them and then paint them back in with the

history brush

6 Select the history brush and start painting As you do, you’ll paint with the

filtered version of the image For my part, I set the blend mode to Darken andpainted around the island country to give it a digital edge, as in the first exam-ple of Figure 7-36

Figure 7-36: I set the brush mode to Darken and painted in the Mosaic effect with

the history brush (left) Then I changed the brush mode to Overlay and brushed inthe Emboss effect (right)

7 Switch the source state by clicking in front of the second filter effect.

Naturally, I clicked in front of the Emboss item

8 Paint again with the history brush This time, I changed the brush mode to

Overlay and painted randomly over Japan and the surrounding ocean Theresult appears in the second example of Figure 7-36

After you finish, you can toss the filtered states This alternate timeline has servedits purpose Or keep it around as a snapshot to come back to later

The art history brush

With the art history brush, you can create impressionistic effects with the aid of the History palette Try this Open any old file Then press D to get the default fore-ground and background colors and press Alt+Backspace to fill the entire image withblack Then select the art history brush, which shares a flyout menu and keyboardshortcut (Y) with the history brush Now paint inside your black image Each strokereveals a bit of your image in painterly detail, as illustrated in Color Plate 7-2

ate tapering and fading strokes using either a mouse or a pressure-sensitive palette.

Read about these options in Chapter 5 as well

Figure 7-37: Select an option from the Style menu to change the type of strokes

applied by the art history brush

The remaining options work as follows:

✦ Style: The art history brush paints with randomly generated corkscrews of

color You can decide the basic shapes of the corkscrews by selecting an optionfrom the Style pop-up menu Combine these options with different brush sizes

to vary the detail conveyed by the impressionistic image Tight and smallshapes give you better detail; loose and big shapes produce less detail

✦ Fidelity: The brush colors each corkscrew according to a color lifted by the

cursor from the original source state Lowering the Fidelity value lets thecorkscrew color drift away from the source color This results in random color-ing (true to the impressionist tradition) but slows down the brush’s response

✦ Area: This value defines the area covered by a single dollop of paint Larger

values generally mean more strokes are laid down at a time; reduce the valuefor a more sparse look

Spacing: This option, formerly known as the Tolerance value, limits where the art

history brush can paint A value of 0 lets the brush paint anywhere; higher values

let the brush paint only in areas where the current state and source state differ in

color

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