Photoshop Lab Color- P12

Photoshop Lab Color- P12: LAB has a reputation for enormous power, yet virtually all referencematerials that advocate its use illustrate its capabilities with a singleclass of image. This chapter introduces the basic LAB correction methodand explains why it is so extraordinarily effective. if you happen tohave a picture of a canyon.
Nội dung trích xuất từ tài liệu:
Photoshop Lab Color- P12 A BFigure 16.8 Left, the original (Figure 16.1A) repeated for convenience. Right, the final sharpened version. The image of the younger woman mea- able to see the adjustment in the man’s hairsures as having a slight red cast, on the rea- color that occurred between Figures 16.9 andsonable assumption that both the hair and 16.11. And the color change in the youngerthe background should be neutral. In glam- woman is obvious, and disagreeable—mut-our photography like this, a warmer feel is ing the red cast has made the skin too gray.often desired, so I suspect the photographer Fortunately, working in LAB means neverdid this on purpose. Nevertheless, the recipe having to worry about tepid colors.calls for taking it out. Next comes the intermediate step of look- The man’s hair has a slight bias toward ing for strong reds. I see none in any of themagenta, but the image’s midrange seems three. On to Step Two, converting to LABfine. Therefore, I lightened the darkest areas and flattening the images, and to Step Three,of the green channel with a curve. the creation of a duplicate layer for overlay There appears to be no color problem with blends to the A and B.the older woman. So, we proceed to Step The paths diverge here, because weOne of the recipe, applying the green channel have three sharply different complexions. Asof each to the composite image on a new noted earlier, the lighter the complexion, thelayer set to Luminosity mode. The results are more it should favor use of the B; the darker,shown in Figure 16.11. the A. The three results of the overlay step As expected, all images have increased are in Figure 16.12. They’re all intentionallycontrast, and are somewhat darker, which too colorful, and all made with different over-we’ll take care of later in LAB. You should be lay percentages.332 Chapter 16 • 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 B but 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 A and B channels. • In Caucasians with unusually darkFigure 16.9 Three original portrait files. A Face Is Like a Canyon 333skin or other individuals who are atleast that dark, and particularly inAfrican-Americans, excessive yellow inthe fleshtone is objectionable. For theman pictured here, I reversed the ratioused for the older woman. I accentu-ated the magenta component of hisskin more than the yellow, by usingoverlay opacities of 100% for the A and75% for the B. Step Four consists of choosing howto split the difference between eachof the bland versions of Figure 16.11,which are on the bottom layer, and theexuberantly saturated ones of Figure16.12 on the top. For the young woman,I chose an opacity of 70%, which is tosay, a lot closer to the colorful versionthan to the dull one. For the olderFigure 16.10 The same images after application ofthis chapter’s recipe.334 Chapter 16 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 L channel. To- gether, they are responsible for addingFigure 16.11 The green channel of the RGB originalshas been applied to each composite image in Lumi-nosity mode, a step analogous to that shown in Figure16.1B. The two right-hand images have had slightcolor adjustments prior to the luminosity blend. A Face Is Like a Canyon 335contrast in a recipe that, being LAB-oriented, keeps color and detail in sep-arate compartments. For the color partof the equation, see how the lips in allthree individuals break away from therest of the face in the corrected versionfar more than in the original. That’sthe AB influence, something that can’tbe duplicated by increasing saturationin other colorspaces.But Here Is the Best PartAs LAB is the choice of those who areyoung at heart, it is appropriate thatwe end our discussion with the faceFigure 16.12 The images shown in Figure 16.11 havebeen converted to LAB, where, on a separate layer, theA and B channels were applied to themselves inOverlay mode. These versions are intentionally madetoo colorful so that a final choice of color can be madeby finding a suitable point between ...