Real World Adobe® Photoshop® CS2 [Electronic resources] : Industrial-Strength Production Techniques نسخه متنی

Retouching

Everyone has their own tolerance level of what can or should be changed in a photograph. We've heard photographers argue convincingly that each time you manipulate an image, especially when you add or remove real objects, it erodes the credibility of photography as a representation of the real. But we've heard other photographers argue equally convincingly that they've never seen a piece of reality they didn't want to improve. We don't have an answer to this debate, but we urge you to at least consider the question.

It's useful to make the distinction between "dust-busting" (removing specks of dirt, dust, mold, hair, and so on) and "retouching" (actually changing the content of an image). In many cases, the tools and techniques overlap, but dustbusting and retouching typically happen at different timeswe prefer to do dustbusting early in the workflow, and whenever possible, do it once (since it's about as much fun as a root canal). In this section, we'll relay a few key pointers that we've learned over the years about both dustbusting and retouching images, in the hope that they'll make you more efficient in whatever work you're undertaking.

Dustbusting

While dust tends to be a bigger problem with film scans than with digital captures, the latter are by no means immune either. Images that don't require dustbusting tend to be the exception rather than the rule. We generally dustbust early in the editing process. We usually do any noise reduction and make basic global corrections to tone and color before dustbusting.

Tip: Retouch on a Layer

However you retouch your imagewith the Clone Stamp tool, the Healing Brush, painting, copying pixels from other portions of the image, and so ontry to do the work on a separate layer. When your edits are on a separate layer, it's easy to erase a change, and it's easy to see "before-and-after" views by turning the layer's visibility off and on. Remember that if you're using the Clone Stamp tool or one of the Healing Brushes when painting on a separate layer, you need to turn on the Use All Layers checkbox in the Options bar.

An alternate method is to create a new layer containing merged copy of all the underlying layers by making a new layer and pressing Command-Option-Shift-E (or choosing Merge Visible from the Layer menu while holding down the Option key). That way we can turn off Use All Layers, which can speed things up slightly, at the cost of a larger file size.

The Healing Brushes and the Patch Tool

Photoshop introduced two new tools that should make even the most hardened retoucher crack a smile: the Healing Brush and the Patch tool. The Healing Brush (press J) is quite a marvel of modern science; you first pick a spot on your image from which you want to clone (like the Clone Stamp tool, you Option- or Alt-click to pick the source), and then you paint in the area you want to change (see Figure 12-23). While the mouse button is down, the screen looks as though you were using the Clone Stamp tool. However, when you let go of the mouse button, Photoshop uses a complicated algorithm to blend the image of the source layer with the tone and texture of the area you're painting. The result is a Clone Stamp tool that blends in better than the Clone Stamp tool ever could.

In Photoshop CS2, things get even better thanks to the debut of the new Spot Healing Brush. The Spot Healing Brush does away with the pesky requirement to choose a source pointinstead, it automatically samples the surrounding area. Figure 12-24 shows an image with its fair share of flawsthe typical dust, hair, and scratches that often bedevil film.

The Spot Healing Brush handles the dust spot flawlessly just by clickingwe used a small brush just big enough to cover the spot. For the hair, we simply painted over the hair by dragging the Spot Healing Brush, again using a brush just wide enough to cover the flaw. The scratch proved slightly more problematic: Often, we can fix scratches like this by clicking the Spot Healing Brush at one end of the scratch, holding down the Shift key, and clicking at the other end of the scratch to paint in a straight line with the Spot Healing Brush. This worked everywhere except where the scratch crosses the horizon (see Figure 12-25).

When a situation like this arises, our first instinct is often to hit Undo, but since the repair was good everywhere except on the horizon, a better starting point for the solution is to use the History Brush to paint out only that part of the repair that didn't workwe set the History Brush Source to the step before the scratch healing, then clicked with a History Brush sized to cover the artifact. In this case, we made the repair by zooming to 300% view, then painting with a very small (3-pixel) Spot Healing Brush (see Figure 12-26). In more difficult cases, we may use either or both of the following tips.

Tip: Watch Out for Edges

The main problem with the Healing Brush and the Patch tool is that they don't work particularly well along edges in your image. For instance, let's say you have a shot of a dark-haired model against a light backdrop. These tools work beautifully in the model's face, but they can cause a mess when used along the edge where the hair meets the backdrop. The reason? These tools rely on the pixels around the brush stroke to blend in properly. Near high-contrast edges, the algorithm breaksin this case, the dark pixels of the hair would smear into the lighter background pixels. The solution: make a soft-edged selection around the area you want to change; these tools won't take the areas outside the selection into consideration, so you won't get this smear effect.

Tip: Replace Mode

When you have the Healing Brush selected, you can select something called Replace from the Mode popup menu in the Options bar. The idea is simple: The Clone brush doesn't work particularly well with soft-edged brushes (the edges get too blurry). The Healing Brush set to Replace mode acts just like the Clone Stamp tool, but works much better if you have a hankerin' to use a soft-edged brush.

The Patch tool is like a combination of the Healing Brush and the Lasso tool. Drag the Patch tool around an area you want to fix like you would make a selection with the Lasso tool (Option-click to create straight-line segments). Then click inside this selection and drag it to the part of your image that you want to copy. When you let go of the mouse button, Photoshop clones that source area over the area you first selected, and then performs its "healing" algorithm to blend the source in properly (see Figure 12-27).

We find that the Patch tool rarely makes a perfect fix, and the results usually need to be cleaned up with the Healing Brush or Clone Stamp tool. But using it and then cleaning up the details is still significantly faster than not using the Patch tool at all.

Dust and Scratches

Anti-Aliasing and Feathering" in Chapter 8, Making Selections).

Feathering is like applying a Gaussian Blur to the edges of a selection: it blends the selected area smoothly into the rest of the image. How much to feather depends entirely upon the image and its resolution, but even a little feathering (two or three pixels) is much better than nothing.

On the other hand, we find that using a soft brush when dustbusting often kills the grain or texture of an image, so we typically use a harder-edged brush or selection for this sort of work.

Tip: A Myriad of Small Spots

Mildew, dust, bugs, corrosives, abrasive surfaces, or even a mediocre scanner can cause hundreds or thousands of tiny white or black spots in an image. And after sharpening, these spots pop out at you like stars on the new moon. If you're like us, you're already cringing at the thought of spot-healing all those dots out.

Here's a technique that can stamp out thousands of dust spots in a single move. You still may have to use the Healing Brush tool to get rid of a few artifacts and some of the larger spots, but most of your work is already done (see Figure 12-29).

At first, this seems like it takes a lot more work; but with experience, you'll find that you can make the right selections very quickly, and the dust spots simply disappear. Note that instead of using the Lighten or Darken blend mode, you can use the layer blending technique outlined in "Tip: Layer Blending Is Fast Blending," later in this chapter. Layer blending takes more time, but offers more control.

The Clone Stamp Tool

The Clone Stamp tool (which was once called the Rubber Stamp tool, though we have no idea why) lets you copy pixels from any place in your image (or even another image) and then paint them someplace else: Option-click to pick up a source point, and then paint away elsewhere to copy those pixels. Remember that you can control the opacity and blending mode of the tool using the Options bar or with keystrokes (see Chapter 2, Essential Photoshop Tips and Tricks).

Tip: Unlimited Cloning Supply

Don't let the boundaries of your image's window restrict you. If you want to clone from another open document, go right ahead and do it. You don't even have to switch documents, as long as you have a large enough monitor.

Tip: Keep Jumping Around

The single biggest mistake people make when using the Clone Stamp tool to clone from one area to another is dragging the mouse in a painting fashion. You should almost never paint when cloning. Instead, dab here and there with a number of clicks.

One exception to this rule is when the area you're cloning is relatively flat and has little texture or detail (like the blurry background behind a portrait). The second exception we make is when we're using the Clone Stamp tool with a blending mode like Darken, Lighten, Soft Light, and so onand then only when the effect is subtle and doesn't create an obvious clone.

A second mistake people make is continuing to clone from the same area. Keep changing the source point that you're cloning (the point on which you Option-click). For example, if you're erasing some specks of dust on someone's face, don't just clone from one side of the specks. Erase one speck from pixel information to the left; erase the second speck from the right, and so on. That way, you avoid creating repeating patterns, and make the retouch less obvious (see Figure 12-30).

There are times, of course, when both these pieces of advice should be chucked out the window. For example, if you're rebuilding a straight line by cloning another parallel line in the image, you'd be hard-pressed to clone it by any other method than painting in the whole line. The following tip provides a way to do so relatively painlessly.

Tip: Stroking Paths

If you're trying to get rid of long scratches in an image, or to clone out those power lines that are always much more noticeable in a photograph than they were in reality, you can use the Pen tool to define a path, then use the Clone Stamp tool to stroke the path, obliterating the offending pixels in one swell foop (see Figure 12-31).

Presto, the scratch is gone. The keys to making this technique work are careful selection of the brush size and source point. If the brush is too big (or small), or your source point isn't aligned correctly, you may wind up duplicating the scratch instead of removing it. However, with a little practice you can make this work very quickly and easily.

Red-Eye

A common retouching task is removing red-eyethat devilish effect that appears when a camera flash reflects off the retina. Ideally, you'll avoid red-eye by using off-camera flash, but if your (or someone else's) photograph already has red-eye, you'll have to remove the red. The new Red Eye tool (it shares a tool palette slot with the Healing Brushes and the Patch tool) is by far the easiest way of doing so, but sometimes it removes the eye color too, so we still resort to the following techniques when necessary.

Hue/Saturation

Select the offending pupils with an oval marquee, feather the selection by a few pixels, copy the selection to a new layer (Command-J), and then use Hue/Saturation to shift the color, brightness, and saturation. Every image requires different values, but we usually start with Hue at +40 (for brown eyes) or 120 (for blue eyes), Saturation at 75, and a Lightness value of 50. The key is to remove the glaring color while still maintaining the specular highlights and color that make the eye look alive.

Color Replacement tool

The Color Replacement in Photoshop CS2 now shares a slot with the Brush in the Tool palette. It lets you change the color of pixels to the foreground color, but leave the pixels' saturation and brightness alone. In other words, it changes the color but retains the detail. We haven't found it useful for large areas, but it's quite good at fixing things like red-eye. Hold down the Option key and click on the darkest part of the eye (or some other dark area nearby), then let go of the Option key, adjust the brush size to slightly smaller than the pupil, and draw over the red portions. You may need to increase the Tolerance level in the Options bar to 35 or 40 percent.

Perspective Retouching

One of the whizzier new features in Photoshop CS2 is the Vanishing Point filter, which lets you clone while preserving perspective, a task that even the studliest pixel-pusher has long found daunting. Vanishing Point makes editing in perspective orders of magnitude easier than it used to be.

Vanishing Point is a very deep plug-in, and if you plan to use it a lot, we strongly recommend reading the online help and mastering the considerable number of keyboard shortcuts. Perspective cloning isn't something we do a lot, so we'll barely scratch the surface here, but we hope to at least give you an idea of the process and a hint of the power.

Lens Correction" in Chapter 9, Sharpness, Detail, and Noise Reduction).

Defining the planes

The first step in using Vanishing Point (after choosing the feature from the Filter menu or pressing Command-Option-V) is to define a perspective plane by clicking on four points (see Figure 12-32).

Then enlarge the plane to cover the area you want to affect, as shown in Figure 12-33. Watch the color and size of the grid when dragging its corners or sides: Red means the grid is not a valid perspective; yellow is pretty close, and blue is good. But in general it's better to see a grid of bigger squares than smaller rectangles. Sometimes moving the grid corners by a pixel or two will make a big difference in the quality of the perspective.

Performing the cloning

Once you've defined the plane, you can use the marquee or clone stamp tool to clone regions in the image, or paste elements from other images. In this simple example, we used the marquee to select the light fixture, then Option-dragged it to create duplicates. Note that the selection created by the marquee automatically conforms to the perspective plane (see Figure 12-34).

In this simple example, we used a single perspective plane, but once you've defined the basic plane, you can automatically create perpendicular planes by Command-dragging an edge node. And while we generally find that it's easier to fine-tune the result on a layer after we've run Vanishing Point, the Transform tool in Vanishing Point lets you transform floating selections.

For more complex cloning operations, we use Vanishing Point's Stamp tool, which works just like the Clone Stamp tool in Photoshop. Figure 12-35 shows before-and-after versions of Bruce's unsanctioned remodel of a listed building in the heart of mediaeval Edinburgh.