Photoshop cs5 cho nhiếp ảnh gia part 29 potx

Using the Refine Edge Controls the Refine Edge tool Figure 4.29 has been completely overhauled in Cs5 to make it even more powerful and easier to use.. When using the selection tools, a

detailed areas, we can make reasonably accurate selections in many cases, as shown in

Figure 4.28

Figure 4.28 It was easy to make a reasonably good

selection of the penguin by using the Quick Selection tool We’ll need to use Refine Edge (covered in the next section) to perfect the selection of the tail

if the selection is not updating fast enough, you may need to drag a little more slowly and continue to hold down the mouse

if you stop dragging and then click elsewhere, the tool will automatically change

to add to selection the selection will grow to incorporate the new area but not

neces-sarily areas in between the original selection and the new area

to remove an area from the selection, choose the subtract from selection option

in the options bar and then drag over the area to be removed You may need to reduce

the size of the tool

in areas of lower contrast, you may need to alternate between adding to and subtracting from the selection Holding down the alt/option key will enable you to

rapidly toggle between the two modes as you do so, Photoshop is actually refining

the algorithm to make the selection more accurately and quickly

to further adjust the edges of the selection, click the Refine Edges button, dis-cussed in the next section

Using the Refine Edge Controls

the Refine Edge tool (Figure 4.29) has been completely overhauled in Cs5 to make it

even more powerful and easier to use its purpose is to enable you to modify the edges

of a selection so that it blends with or separates from the background as needed

When using the selection tools, a Refine Edge button appears on the tool

Mask Edge button it is our method of choice for controlling the appearance of the

edges of a selection no matter how we made the initial selection it’s taken the place

of the simple Feather command in our workflow and it eliminates the need for the

elaborate procedure we used to use, in which we created a layer mask for a selection

and blurred the edges of the layer mask

the Refine Edge interface is divided into several sections View Mode contains options for viewing the selection By default it places your selection against a white

background, but it is sticky and will open with the view you used last Click the View

drop-down menu to access other choices the edges of some selections will show up more easily against black or with the red overlay or even as black and white or against a transparent background if you can’t easily see the edges of your selection, choose a dif-ferent view Press F repeatedly to scroll through the difdif-ferent View options (Figure 4.30)

Figure 4.29 The Refine Edge dialog

box provides tools to perfect the edges of the selection

Standard

Quick Mask

On Black

Figure 4.30 Depending on the image, different previews make it easier to see the edge

detail of the selection

Cs5 has two new Refine Edge View modes on Layers shows the unmasked image data on its own layer, along with the other image layers below this enables you

to create your own color fill layer right below the masked layer if you’d like to view the

selection against a different color background We rarely find this necessary, but in

cer-tain tricky situations it might be helpful the Reveal Layer view disables the layer mask

so that you see the entire active layer as though there were no mask (although color

decontamination is applied.) it’s a quick way to see how the selection and edges fit into

the rest of the image

after you’ve modified the edge, check show original, or press P, to compare the new edge with the original Check the show Radius box to view the area that’s

defined as an edge that way you’ll know exactly where the Refine Edge tool will

affect the selection

use the zoom tool and the Hand tool on the upper left of the dialog to increase the magnification to work in detail on certain areas as necessary

the Edge detection slider is used to help Photoshop choose a narrower hard edge

or a wider softer edge containing areas of varying transparency a selection of a fence

against grass would require a fairly hard edge, whereas selecting fur or feathers (or hair)

would require an edge with larger areas of transparencies to let the background show

through increase the Radius slider to choose the width of the edge For the penguin,

Ellen chose a moderately wide radius to help with the tail selection

after setting the Radius slider to the maximum amount of refinement you want, check the smart Radius option to have Photoshop automatically reduce the level of

refinement that occurs around certain localized areas of the mask edge this way

Photoshop can scale down the amount of refinement applied to simpler edges, which

decreases the risk of noise artifacts from the background

brush over the edges you want to enlarge to select the penguin’s tail feathers, Ellen

brushed over the tail several times, and the selection became increasingly more accurate

Choose the Erase Refinements tool (from the same icon by holding the lower-right corner and clicking the tool from the pop-up menu) to decrease the edge

refine-ments in certain areas When using these tools, it can sometimes be helpful to check

the show Radius option in the View Mode section

Larger radius settings preserve more details along the edges but may include some artifacts You can remove such artifacts by increasing the Contrast slider in the

adjust Edge section in addition, increasing the contrast retains gradual transitions in

larger areas but makes slightly soft edges crisper

next adjust the smooth slider to reduce any jagged edges along the edge of the selection at times this may cause some fine detail to be lost in such cases, adjust the

Radius slider to recover the detail

the Feather slider is similar to the familiar Feather command from earlier ver-sions of Photoshop it produces a uniform, gradual blur along the selection edge the

Radius slider is a more sophisticated version of feathering We recommend primarily

using the Radius slider and using Feather just for any fine-tuning the edges need

Moving the shift Edge slider to the left contracts the selection and moving it to the right expands the selection

in the output section, by default output to will be set to either selection or Layer Mask, depending how you accessed the Refine Edge dialog if you are on a pixel

layer (rather than an adjustment layer), you will also have the option to check decon-taminate Colors in some cases the edges of the selection will be partially transparent and allow some of the original background color to come through the decontami-nate Colors option will change the color of those partially transparent pixels to hide all traces of the original background set the amount as needed via the amount slider

if you use the decontaminate Colors option, the output to drop-down menu will automatically change to new Layer with Layer Mask, although you can also choose

to output to a new document with or without a layer mask We primarily choose the new Layer with Layer Mask option

if you create a series of settings that you want to use frequently as your starting place, check the Remember settings option

By using the Refine selection tools, you can control the appearance of the edges

of your selections to make transitions that blend naturally into the rest of the image

Combining the Quick select tool and Refine Edges made it quick and easy to accu-rately select the penguin, including the fine details of his tail, as shown in Figure 4.31

Figure 4.31 The new Refine Edge tool made it easy

to perfectly select the penguin as well as his tail feathers

For Photoshop Elements Users: Refine Edge

The Elements Refine Edge window is more basic than the CS5 tool, providing only Smooth, Feather, and Contract/Expand options, as seen here Furthermore, the Elements version of Refine Edge has only the Standard and Quick Mask preview modes

Creating a Custom Image Border Using Refine Edge

It’s easy to create a custom edge border as shown here using the Refine Edge tool Begin by making a selection with the Rectangular or Elliptical Marquis tool close to the border of the image Then choose Refine Edge Experiment with a large Radius setting and then adjust the Contrast, Feather, and Shift Edge settings as desired Check Smart Radius and see how it affects the result Use the Refine Radius tool on some of the edges if needed

Color Range Tool

the Color Range tool is similar to the Magic Wand tool but far more powerful it

enables you to select multiple areas of the same or different colors at one time it’s

particularly useful in selecting skies when there are objects such as trees in the

fore-ground to access it, choose select > Color Range

We leave the select drop-down box set to sampled Colors most of the time, but

on occasion we might set it to Highlights or shadows to make a selection of just those

tonalities While you could use any of the options, most of the other options are more

helpful for graphic artists But if you have a use for a different type of selection, feel

free to try it

We tend to leave the selection Preview at the bottom of the dialog set to none initially, but have the preview itself within the Color Range dialog set to selection (as

in Figure 4.32) at times during the selection process, we might change the selection Preview to Quick Mask, Grayscale, Black Matte, or White Matte to more precisely check the results, but we find that a setting of none provides a good starting place

the Localized Color Cluster option is helpful when you want to make a selec-tion of a color in one part of an image but not in another—for example, in the fore-ground but not the backfore-ground, or blue sky but not blue water in an image it helps you to make a more accurate selection quickly

to use Color Range to select the sky (or anything else) in an image, take the following steps:

eyedrop-per to click an area in your image to specify as the target color (You can also use the pull-down menu from the select box, and choose a specific color, such

as blue, or highlights, midtones, or shadows; but usually it’s more effective to sample the specific color in the image.) You can click directly on the image or

on the small preview in the dialog box

areas are black, and gray areas are blurred selection edges.)

colors; lower values select fewer colors the preview box shows how the Fuzzi-ness value is affecting the selection (see Figure 4.32)

Figure 4.32 With just a couple clicks of the eyedroppers and adjusting the Fuzziness slider, you can easily select a sky from this

image

and click additional areas of the background until you have successfully iden-tified the entire sky area similarly, you may need to use the subtract From eyedropper to remove areas from the selection as you do so, you’ll have to readjust the Fuzziness slider

see the boundaries of your selection, making it easier to set the Fuzziness slider

Choose the selection preview that makes it easiest for you to see the edges of your selection We often find the grayscale view helpful

Figure 4.33 Using the Selection Preview overlay helps you make accurate selections.

the other yellow leaves, you would check the Localized Color Clusters option (Figure 4.34) and then move the Range slider toward the left to limit the geo-graphic area that Photoshop uses for the selection By doing this, we were able

to make a very specific selection that would have required more work using any

of the color-selection tools (the Range slider is active only when Localized Color Clusters is checked.)

Figure 4.34 The Localized Color Clusters option makes

it possible to limit the area that’s selected when the color appears in multiple parts of the image

white area into a selection

and you cannot eliminate them using the subtract From eyedropper, the Fuzzi-ness slider, or the Range slider, use any of the other selection tools (such as the Lasso or Magic Wand tool) to remove them from the selection

eye-dropper and clicking an additional color in your image Similarly, you can use the farthest-right eyedrop-per to click a color range to remove from your selection

the Color Range tool tends to create selections with slightly blurry edges, whereas the Magic Wand creates more definite selections with anti-aliased edges of course, any selection can be modified using the Refine Edge tool

the Masks panel uses the Color Range tool to help create and adjust layer masks We’ll talk more about that in Chapter 6

Combining Tools

We’ve covered some of the key selection tools here to help you build a foundation for the use of tools within Photoshop as well as get you started on creating selections you’ll use to apply targeted adjustments to your images in Chapter 8, “Composites,”

we’ll explore additional, more advanced ways of making selections However, we want

to stress here that you can mix and match any of the selection tools or methods in

Photoshop to create the perfect selection it’s fine, and often helpful, to begin a selec-tion with one tool and use another tool to refine it, as you saw earlier with the combi-nation of Quick select and Refine Edges (Figure 4.31)

in the workshops we teach, we often see participants getting stuck on a single selection tool for a given task For example, if they’re trying to create a selection of the sky, they naturally start with the Magic Wand tool if that tool isn’t providing a good solution in a particular portion of the sky, we often see the person struggling to find just the right tolerance setting and just the right pixel to click in order to get the