Photoshop Lab Color- P12 ppsx

So, we proceed to Step One of the recipe, applying the green channel of each to the composite image on a new layer set to Luminosity mode.. Step Four consists of choosing how to split th

The image of the younger woman mea-sures as having a slight red cast, on the

rea-sonable assumption that both the hair and

the background should be neutral In

glam-our photography like this, a warmer feel is

often desired, so I suspect the photographer

did this on purpose Nevertheless, the recipe

calls for taking it out

The man’s hair has a slight bias toward magenta, but the image’s midrange seems

fine Therefore, I lightened the darkest areas

of the green channel with a curve

There appears to be no color problem with the older woman So, we proceed to Step

One of the recipe, applying the green channel

of each to the composite image on a new

layer set to Luminosity mode The results are

shown in Figure 16.11

As expected, all images have increased contrast, and are somewhat darker, which

we’ll take care of later in LAB You should be

able to see the adjustment in the man’s hair color that occurred between Figures 16.9 and 16.11 And the color change in the younger woman is obvious, and disagreeable—mut-ing the red cast has made the skin too gray

Fortunately, working in LABmeans never having to worry about tepid colors

Next comes the intermediate step of look-ing for strong reds I see none in any of the three On to Step Two, converting to LAB

and flattening the images, and to Step Three, the creation of a duplicate layer for overlay blends to the Aand B

The paths diverge here, because we have three sharply different complexions As noted earlier, the lighter the complexion, the more it should favor use of the B; the darker, the A The three results of the overlay step are in Figure 16.12 They’re all intentionally too colorful, and all made with different over-lay percentages

Figure 16.8 Left, the original (Figure 16.1A) repeated for convenience Right, the final sharpened version.

• Light-skinned Caucasians, such as

the older woman in this set and the

earlier subject of Figure 16.1, generally

need the yellow component of their

flesh emphasized more than the

ma-genta These individuals often can be

identified by their light hair and blue

eyes To make the version in Figure

16.12, I used overlay percentages of

100% in the Bbut only 75% in the A

• Moderate- to dark-skinned

Cau-casians and other groups of similar

skintone don’t require the sort of

artifi-cial suntan we just manufactured

Some persons of Asian ancestry have

skin darker than almost all Caucasians,

but the younger woman shown here

isn’t one of them I used 100% overlays

in both Aand Bchannels

• In Caucasians with unusually dark

332 Chapter 16

Figure 16.9 Three original portrait files.

skin or other individuals who are at least that dark, and particularly in African-Americans, excessive yellow in the fleshtone is objectionable For the man pictured here, I reversed the ratio used for the older woman I accentu-ated the magenta component of his skin more than the yellow, by using overlay opacities of 100% for theAand 75% for the B

Step Four consists of choosing how

to split the difference between each

of the bland versions of Figure 16.11, which are on the bottom layer, and the exuberantly saturated ones of Figure 16.12 on the top For the young woman,

I chose an opacity of 70%, which is to say, a lot closer to the colorful version than to the dull one For the older

A Face Is Like a Canyon 333

Figure 16.10 The same images after application of

this chapter’s recipe.

woman I went to 60%, and in view

of the fact that it is supposed to be a

picture of a businessperson and not a

cooked lobster, only 45% for the man

What would your choices have been?

From this point the steps are

sub-stantially the same as shown earlier

between Figures 16.6B and 16.8 B

There is no need to rehash them here

In comparing the corrected versions

of Figure 16.10 to the originals of Figure

16.9, look around the noses and chins

The greater depth stems from the

original blend of the green channel in

Luminosity mode, aided by the final

curve applied to the Lchannel

To-gether, they are responsible for adding

334 Chapter 16

Figure 16.11 The green channel of the RGB originals

has been applied to each composite image in

Lumi-nosity mode, a step analogous to that shown in Figure

16.1B The two right-hand images have had slight

color adjustments prior to the luminosity blend.

contrast in a recipe that, being LAB -oriented, keeps color and detail in sep-arate compartments For the color part

of the equation, see how the lips in all three individuals break away from the rest of the face in the corrected version far more than in the original That’s the ABinfluence, something that can’t

be duplicated by increasing saturation

in other colorspaces

But Here Is the Best Part

As LABis the choice of those who are young at heart, it is appropriate that

we end our discussion with the face

A Face Is Like a Canyon 335

Figure 16.12 The images shown in Figure 16.11 have

been converted to LAB , where, on a separate layer, the

A and B channels were applied to themselves in Overlay mode These versions are intentionally made too colorful so that a final choice of color can be made

by finding a suitable point between each version and its counterpart in Figure 16.11.

of a child And, as L A B is the choice of

the creative, it is appropriate to recall that

recipes lay an important foundation but that

superior dishes are prepared by those who

can improvise

A smiling little girl surrounded by flowers

can make almost any photographer look

good Indeed, Figure 16.13 is passable just the

way it is A characteristic of those who use

LAB, however, is the gnawing suspicion that

the original image is never good enough

The recipe we’ve been working with so far

won’t work here, at least not without some

preparation It assumes normally lit subjects

This one isn’t The sun is too strong The right

side of the face is heavily in shadow, while the

left side is almost gone Applying the green

channel in Luminosity mode, as we have

been doing, darkens the face, which would be

good for the left side but fatal for the right

As we near the end of a book about LAB

technique, the bag of tricks that we can reach into has become rather large It would be absurd to pretend that there’s one right way

to handle this picture, particularly since, as you’re about to see, the first time I tried it I screwed it up One day I’ll give it out as a class exercise and see what others can make of it

For now, it might be useful to explain what

I see in this original and what I think the choices are

First, the image is full of bright colors, which constitute an argument against using

LAB Anything that intensifies the flowers or the sweater will drive them out of the gamut

of whatever our final output space is

As against that, in LAB, unlike RGB, it’s a snap to exclude those areas from any other work being done on the image Nothing is remotely close to being as A–positive as the flowers are I can enhance the girl’s face on one layer, and if it wrecks the flowers I can

Figure 16.13 The harsh sunlight coming in from the left side is an obstacle to the use of this chapter’s recipe.

restore the originals with one sweep of a

Blending Options slider

The image reminds me of two that ap-peared in the last chapter Another species of

purple flowers graced Figure 15.5, but they

were the most important part of that picture

Here the girl is the focus of attention

How-ever, darkening the flowers and lightening

the greenery worked well there Blending an

inverted copy of the Achannel into the Lin

Overlay mode is therefore an option

Second, the combination of sun and shade

in the face is reminiscent of the hunter of

Figure 15.6 Unfortunately, the light parts of

the girl’s face are much lighter than the man’s

were Any effort to lighten the dark parts of

the face by blending with the Aor Bwill wipe

out the light parts

The Shadow/Highlight command, nor-mally quite potent, was ineffective against

the hunter image, and can’t be expected to

do well here either We need a trick that will lighten the right side of the face (and, if pos-sible, the hair) while darkening the left side

Chapter 15 hinted at how

Overlay mode uses 50% gray as a dividing line Where the overlaying image is lighter than 50%, it lightens the underlying one;

where darker, it darkens If we can find a channel where the two halves of the face fall

on different sides of 50%, we should be able

to make a significant improvement

Once the file gets to L A B (it starts in

RGB, of course), we won’t find such a channel

In both A and Bthe entire face is positive because even in the darkest areas, it’s still a distinctly warm color

The Lwould also not be of use It’s lighter than any RGBchannel, so both halves of the face would probably be lighter than 50% gray

A Face Is Like a Canyon 337

Figure 16.14 Left, the blue channel of Figure 16.13 Right, the channel is blurred and inverted to prepare for a blend.

B A

Unless there’s some major color balance

problem, any face, any race, any age, any

page, any pose, any nose will be lightest in

the red channel and darkest in the blue The

blue (Figure 16.14A), is where we should look

because that’s the one where the right side of

the face is certain to be darkest The left side

can’t possibly be close to 50% in any channel

I propose to overlay this blue channel onto

the composite image It needs to be blurred

heavily first, as otherwise there will be weird

artifacting in sharply defined areas such as

the eyes and eyebrows Therefore, we’ll need

a separate copy of the blue, as we can’t afford

to destroy the existing copy

Also, during the overlay the channel needs

to be inverted Otherwise, the light areas

will get even lighter and the dark ones will plug In real life, we check the Invert box in the Apply Image dialog when popping the blurred blue into the composite For ease of visualizing what is about to happen, how-ever, I’ve inverted Figure 16.14B already Once you get your bearings—it’s cropped exactly as Figure 16.4A is—you can see that it is about

to darken the left half of the face plus the flowers, and lighten almost everything else

Applying it to the composite RGBof Figure 16.13 in Overlay mode, 100% opacity, pro-duces Figure 16.15

The face and hair are greatly improved

The background is interesting, possibly better and possibly not Bad things have happened

to the sweater and the red ribbon

338 Chapter 16

Figure 16.15 Figure 16.14B, a separate channel, is applied to Figure 16.13, Overlay mode, on a new layer.

There isn’t a convenient way to revert to the original sweater in RGB Try to exclude things that

are dark in the blue channel, as the sweater is, and

you get the hair also Exclude things that are light

in the red, and kiss the left half of the face goodbye

If the file were in LAB, the problem would go away, because nothing is nearly as B–positive as

the sweater and the ribbon are The flowers are

magenta, not red; they’re actually B–negative The

face and leaves are B–positive, but far less so than

the sweater

When I first prepared this part of the chapter, I fell into a trap right here Seduced by the great

improvement in color between Figures 16.13 and

16.15, I moved briskly and stupidly into LABso as

to exclude the sweater and ribbon there with layer

Blending Options

We have spent almost 350 pages learning that

LABis the best way to enhance color Blending in

Overlay mode in RGBis one of the worst That it

accidentally produced many good colors to go along

with the ones that it wrecked should not have

blinded me to the principle that overly gray colors

are an utter, complete, total, and absolute non-issue

when LABis right around the corner I should have

(and I did, the second time around, having wasted

about a day preparing these pages with an inferior

method) changed the layering mode to Luminosity

while I was still in RGB, producing Figure 16.16A

It’s grayer than it was, but it retains the excellent

detail that the overlay manufactured in Figure 16.15

Moreover, its new green channel—Figure 16.16B—is

eminently suitable for further blending The recipe is

back on track We’re at Step One

You Have a Head Start

On a new layer, I applied Figure 16.16B to Figure

16.16A in Normal mode, changed layer mode to

Luminosity, and then trashed it because it looked

terrible It had darkened the face, appropriately

Figure 16.16 Top, the layer is changed

to Luminosity mode, restoring the color

of Figure 16.13 Bottom, the green

channel of the top version is now

suit-able for further blending.

A

B

enough, but it had disagreeably weakened the leaves and the sweater, both of which are light in the green channel I therefore redid the layer, this time applying Figure 16.16B in Darken mode, pre-venting anything from getting lighter and producing Figure 16.17A

The recipe calls for checking for dark reds and purples, which this image has in abundance, and for taking them out of the mix by using the Blending Options slider to exclude things that are dark in the green channel While that method works, a more easily controllable one is available, one that permits

me to disallow the darkening of the flowers only partially, something I would like to do

By going to Step Two of the recipe, converting to

LABwithout flattening the file first, not only do I get slightly better color, but I can take advantage of the ability to isolate colored objects in Blending Op-tions To make Figure 16.17B, I used two sliders, both

of which I split by Option–clicking to create a zone

of transition where Photoshop would average the two layers rather than choosing one or the other

TheLchannel slider restores Figure 16.16A fully

in the hair, which is very dark, and partially in the red ribbon, sweater, and darkest areas of the face

There is no impact on the leaves, which are identical

on both layers, thanks to the darken-only blend I used to make Figure 16.16A

The second slider is intended to catch the flowers

They are so strongly magenta-as-opposed-to-green that you might instinctively reach for the Asliders to deal with them That would be a mistake

You could definitely isolate the most colorful areas

of the flowers, which are far more A–positive than

Figure 16.17 Top, Figure

16.16B is applied, Darken mode, to a new layer of Figure 16.16A, set to Overlay mode Below, the file is converted to LAB

without flattening, and portions of the top layer are excluded with layer Blending Options.

A

B

anything else in the picture The problem is

that parts of the flowers aren’t all that

color-ful, and the face, the sweater, and the red

ribbon are all A–positive also You can’t get

all the flowers without picking up pieces of

the other things as well

If you want to make extensive use of LAB

blending options, keep your eye peeled for

B–negatives—objects that are more blue than

yellow Outside of outright blue things like the

girl’s ribbon and a sky, you won’t find many

The LABgreen is already quite blue; to find

something on the blue side of that green is

unusual Things on the blue side of magenta

are also rare, but these flowers qualify They,

and the blue ribbon, are the only B–negative

objects in the entire image It’s a snap to

tar-get them with the slider, and, with nothing

else to get in the way, we can widen or narrow

the transition zone to make the flowers

whatever darkness we like (For more discussion of this color phenomenon, see the box on Page 343.)

After making that decision, and flat-tening the image, I had reached Step Three of the recipe, the color boost

The idea of the step is to create some-thing more colorful than what we want and then back off; hence, we usually overlay either the AorBonto itself at 100% opacity on a new layer, balancing

it with an appropriate amount of the other, and then back off the overall color to taste by reducing layer opacity

This image is so colorful to begin with that I saw no point in going over-board I started by overlaying the A

onto itself at only 80% opacity Then, perceiving a slight imbalance toward yellow, I overlaid the B onto itself at 70%, reaching Figure 16.18

I then reduced layer opacity to 45%

and took care of the remaining recipe steps, which require no comment, except for one final fillip

It seemed to me that the leaves were too light.LABpresents ways to correct this that give more realistic results than those avail-able in other colorspaces, but it’s at least a two-step process that always involves an extra layer and exploits the fact that the leaves are the only A–negative objects

I could apply curves to the top layer and then exclude everything but the leaves using Blending Options in the A, but that would require care to avoid creating obvious transi-tion lines The foolproof method is to blend the Ainto the Lin Overlay mode Doing so darkens the leaves, but it also lightens every-thing A–positive—to wit, the rest of the pic-ture Blowing out the fleshtones that I had been at such pains to develop was unfortu-nate Happily, it is easily reversed by Image:

Apply Image, again with the top layer’s Las target, but using the underlying Las source

A Face Is Like a Canyon 341

Figure 16.18 In a flattened version of Figure 16.17, the A

channel is applied to itself in Overlay mode, 80% opacity, and

the B to itself at 70%.