Photoshop cs5 cho nhiếp ảnh gia part 36 ppt

217 ■ DOING CLEANUP IN PHOTOSHOP The Photoshop Cleanup Tools The Clone Stamp tool, the Healing Brush tool, the Spot Healing Brush tool, the Patch tool, and Content-Aware Fill are all useful in removing dust spots, removing unwanted objects from your image, and even filling in areas when you need to enlarge your canvas. They’re very similar tools, but they’re also different in some important ways. When using any of these tools except the Patch tool, we begin by creating a new layer for the cleanup. To do so, click the Create A New Layer icon at the bottom of the Layers panel next to the trash can. This creates an empty pixel layer on which you will place new pixels to hide the imperfections in your image. By doing the cleanup on a separate layer, you don’t have to worry about permanently changing any pixels in the file. (You can’t use these tools directly on a Smart Object layer.) Since the Patch tool must be used on pixels, rather than creating an empty pixel layer, we begin by dragging the background layer to the Create New Layer icon to duplicate that layer. The Clone Stamp tool may be the easiest to understand. It simply copies the pixels that you specify from one place to another place. To use it, make certain to check Sample All Layers in the tool Options bar, and do the following: 1. Place the cursor over the area from which you want to sample. 2. Hold down the Alt/Option key, and click. 3. Release the Alt/Option key. 4. Position the cursor over the area that you want to replace, and click. It’s that simple! If you just keep clicking to sample an area and then clicking to put it some- where else, you’re likely to end up with a series of circular replacements that are easy to spot. On the other hand, if you click and drag for long distances, you’re likely to get repeated patterns that are also a telltale sign of a poorly optimized image. The trick is to just drag a smidge around the replacement area and make certain not to have an identifiable repeated pattern. Most of the time you should make sure to use a soft brush and adjust the size of the brush, using the bracket shortcut keys as explained in Chapter 4 so that the brush is just slightly larger than the smaller dimension of the dust you’re trying to remove. If you are cloning out a large area, you’ll have to use a small enough brush to be able to convincingly re-create the background. You need to think like an artist and select pixels to use to re-create that area of the picture. Note: CS5 includes two new icons for use with pen tablets on the tool Options bar for the Clone Stamp, Healing Brush, and Spot Healing tools. Both override the settings in the Brush panel. makes pen pressure control the effective brush size, whereas makes pen pressure control opacity. You can use one or both. This is a convenient way to quickly and temporarily change the effect of pen pressure. We find that using pen pressure to adjust opacity makes it easier to make the cloning we do look natural. 607343c05.indd 217 4/13/10 2:44:12 PM 218 c h a p t e r 5: WORKFLOWS AND FIRST STEPS ■ It’s important to remember to have Sample All Layers checked in the Options bar at the top of your screen. If it seems like nothing is happening, it’s probably because this isn’t checked. Also make sure the No Adjustment Layers icon in the Options bar is turned on so that adjustment layers are ignored when cloning. That way, if you return to the cleanup layer after you’ve made some further adjustments, you won’t have to manually turn off the adjustment layers as you did with versions of Photoshop prior to CS3. (Otherwise, if you clone on a lower layer after you’ve added adjustment layers, the adjustments are applied twice to the cloned pixels and that causes the cloned areas not to match the image.) Most of the time, you also want Aligned checked. This means that the source you are sampling from moves in conjunction with the movement of the cursor at the destination. Otherwise, every time you unclick and then click to continue cloning, the source resets to where you initially began sampling. That tends to cause repeated p a t t e r n s . There is a Clone Source panel (Figure 5.18) in Photoshop (but not Elements) in which you can specify several different sources for your cloning. The sources can be located in the same image or in different images. To create a source preset, click one of the Clone Source icons, then hold the Alt/Option key and click the desired point in the image; a target with a number will mark that spot. This is helpful so you can easily identify which clone source to use. Although we don’t often find this too useful with nature images, you may encounter certain situations where using multiple source presets would be very helpful. For example, if you remove an object or add canvas and need to create a new area of background, it might be helpful to have several different source points preselected on other images with similar backgrounds. CS5 adds an icon in the tool Options bar to make it easier to have the Clone Source panel appear when you need it. Note: If you discover that you need to clone the mirror image of your source, perhaps to repair an ear or a wingtip from the opposite body part, use the Clone Source panel and click the Flip Horizontal or the Flip Vertical icon. Figure 5.18 The Clone Source panel adds several features to the Clone Stamp tool, including presets, the Show Overlay option, and the ability to ip the clone source. 607343c05.indd 218 4/13/10 2:44:13 PM 219 ■ DO ING C LEA NU P IN PHOTOSH OP We find that the Show Overlay option in the Clone Source panel is very helpful. By checking this option, an overlay of the source you’re using appears superimposed within the brush (Figure 5.19). That makes it easier to know where to begin and how far to drag when cloning. Figure 5.19 Using the overlay when cloning makes it easy to see where to begin and how far to drag the brush. Photo by EllEn Anon For Photoshop Elements Users: Overlay Option Elements does have options for showing an overlay. To reveal them, click the Overlay button in the Workspace Buttons bar. We recommend selecting Show Overlay and Clipped so that you see the overlay image clipped to your current brush. The Healing Brush tool operates very similarly to the Clone Stamp tool. Press Alt/Option and click to define the source area, then release the Alt/Option key and click the area you want to change (the destination). However, the Healing Brush in Normal Mode copies the texture of the source area and blends the colors so that a natural-looking correction results, in which texture has been added and color has been blended from the source and destination. This can be quite useful to create natural- looking corrections, especially in areas of sky and clouds. Its behavior initially seems less predictable when used near edges with strongly contrasting tonalities. In the Options bar, make sure that Source: Sampled is checked and that Pattern is unchecked. As with the Clone Stamp tool, you usually want Aligned and Sample All Layers checked as well. Adjust the brush size and hardness as with the Clone tool. If the results seem to be smudged, try changing to the Replace mode. This changes the algorithms Photoshop uses so that it applies a special blending that is better at preserving some high-frequency data, including details and noise. In many cases the For Photoshop Elements Users: Overlay Option Elements does have options for showing an overlay. To reveal them, click the Overlay button in the Workspace Buttons bar. We recommend selecting Show Overlay and Clipped so that you see the overlay image clipped to your current brush. 607343c05.indd 219 4/13/10 2:44:13 PM 220 c h a p t e r 5: WORKFLOWS AND FIRST STEPS ■ results will be similar to using the Clone Stamp tool, although there may be better blending. The Spot Healing Brush operates like a “smart” Healing Brush. You don’t have to define a source; instead you simply click the tool and then click and drag your cursor over the area that needs fixing. Photoshop automatically looks at the surrounding pixels and decides what pixels to use to modify or replace the ones that you brush over. The Spot Healing Brush can also be used in a variety of modes, although primarily you’ll use Normal or Replace. Usually the Spot Healing Brush works best if the brush is a little larger than the narrowest dimension of the area to replace, but just one click of the bracket keys larger than what you would use with the regular Healing Brush. Content-Aware Healing In CS5, the Spot Healing Brush has an option to set the Type as Content-Aware rather than Proximity or Texture. In earlier versions of Photoshop, nature photographers needed to rely on the Proximity option. However Content-Aware uses some impressive, sophisticated algorithms to analyze the areas that surround the problematic area and then determine what pixels to use to make the replacement area blend in with the surrounding pixels. In many images Content-Aware tends to work far more accu- rately than Proximity Match, which uses slightly different algorithms to analyze the surrounding pixels. In fact, in some situations Content-Aware is absolutely amazing! For example, it did an impressive job of removing the pole and the power line behind the elephants in Figure 5.20. In many ways this is a long-awaited power-line filter! In other situations, the Spot Healing brush, with Content-Aware selected, provides a good starting place, but you may have to use the Clone Stamp tool along with the regular or Spot Healing brushes to finish up. Occasionally you may opt to use Proximity if you’re not getting the results you desire with Content-Aware, but in most situations we prefer Content-Aware. We’ve found that the Spot Healing Brush, particularly with the new Content- Aware option can be a huge time-saver. You may need to experiment with the Normal and Replace modes to see which works better for you. We think that the Replace mode tends to work better in areas with more detail, while Normal may produce better results in areas with less detail. Note: If initially the Spot Healing Brush gives you an unacceptable result, adjust the size with the bracket key to slightly larger or smaller, and try again. Often a slight adjustment to the brush size or the direction that you drag enables Spot Healing to work effectively. Using these tools well takes some practice. Be careful not to create repeated patterns that make it obvious you “fixed” something. Taking the time to do a careful job in removing unwanted areas and re-creating background areas is well worth it if you want the image to look natural. 607343c05.indd 220 4/13/10 2:44:13 PM 221 ■ DOING CLEANUP IN PHOTOSHOP Figure 5.20 The new Content Aware setting can make it easy to remove unwanted wires, poles, and other objects in images. Ph oto by EllEn Ano n Try It! To get familiar with the behavior of these tools, open the image called Cloning on this book’s companion website, www.sybex.com/go/photoshopnature, and play with each tool, noting what happens when you sample in one colored or textured area and then try to heal or clone to the same or a different area. See how each tool behaves in each situation and near edges. Don’t forget to work on layers! The Patch tool is another cleanup tool. It can save time in repairing larger areas. To use the Patch tool, click the icon from under the Healing Brush tool. Then choose Source in the Toolbar Options. Make a selection around the area that needs fixing, and then drag the selection to other areas of the image to find one that is suitable. Similar to the other healing tools in Normal mode, the Patch tool will copy texture and blend color. This limits its usefulness in our experience. 607343c05.indd 221 4/13/10 2:44:15 PM 222 c h a p t e r 5: WORKFLOWS AND FIRST STEPS ■ Darrell Gulin offers the following cleanup suggestion based on his workflow for creating dramatic images of butterflies and moths. Repairing Wings Using the Patch Tool by Darrell Gulin Continues 607343c05.indd 222 4/13/10 2:44:15 PM 223 ■ DO ING C LEA NU P IN PHOTOSH OP Repairing Wings Using the Patch Tool (Continued) When I raised the Papilio hoppo swallowtail butterfly I had to wait six weeks for this very special, expensive, butterfly to hatch. When it did, it immediately went to the carpet and just damaged its wings and knocked off many of it scales. This is where the Patch tool came to the rescue. I used it to repair all of the scale damage. The freesia flowers were in need of repair too, and the Patch tool was used there also. I used the Patch tool in the Source mode and circled the area that needed repair, and then I moved the circle to the area that I wanted to be picked up and used. To replace the missing tail, I used the Lasso to select the good tail. I placed this selection on a new layer and then moved, flipped, and transformed it to make it appear natural. Then I added a layer mask to that layer and brushed in the background. Most of the time, though, the Patch tool is all I need. In fact I use the Patch tool so much I have changed the P key to give me the Patch tool as a shortcut. Give it a try. CS5 adds a new way to fix larger areas, called Content-Aware Fill. The idea is to use the same technology developed for the Content-Aware Spot Healing Brush, but on larger areas. To use Content-Aware Fill, take these steps: 1. Make a selection of the area to be replaced. Often you’ll do this using the Quick Selection tool, but you can make the selection any way that’s convenient. 2. Go to Select > Refine Edge and choose settings to soften the edge and make the selection slightly larger. The actual numbers you use may vary according to the specifics of the image, but we often try setting Smooth to 50 and Shift Edge to 50%. 3. Go to Edit > Fill. Select Content-Aware from the Use pop-up menu and click OK. The area you selected will be replaced by surrounding background pixels. When you zoom in to a higher magnification, you may discover that you need to do more final touch up work. Nonetheless, Content-Aware Fill is a huge timesaver when you’re faced with removing or filling in significant areas in an image. We’ll put it to use later in the chapter when we add canvas to an image. Once you’re familiar with the tools, you’ve examined your photo, and you have a layer available, you’re ready to put these tools to work to clean up your image. Removing Dust In most cases, removing the spots created by dust and dirt on your camera’s imaging sensor is a relatively easy job. Create a new layer as described earlier, zoom in, and begin carefully navigating throughout your image, checking for dust (see Figure 5.21). Our first choice for removing these spots is the Content-Aware Spot Healing Brush in Repair mode for detailed areas and Normal mode for less detailed areas. At times you Repairing Wings Using the Patch Tool (Continued) When I raised the Papilio hoppo swallowtail butterfly I had to wait six weeks for this very special, expensive, butterfly to hatch. When it did, it immediately went to the carpet and just damaged its wings and knocked off many of it scales. This is where the Patch tool came to the rescue. I used it to repair all of the scale damage. The freesia flowers were in need of repair too, and the Patch tool was used there also. I used the Patch tool in the Source mode and circled the area that needed repair, and then I moved the circle to the area that I wanted to be picked up and used. To replace the missing tail, I used the Lasso to select the good tail. I placed this selection on a new layer and then moved, flipped, and transformed it to make it appear natural. Then I added a layer mask to that layer and brushed in the background. Most of the time, though, the Patch tool is all I need. In fact I use the Patch tool so much I have changed the P key to give me the Patch tool as a shortcut. Give it a try. 607343c05.indd 223 4/13/10 2:44:16 PM . 217 ■ DOING CLEANUP IN PHOTOSHOP The Photoshop Cleanup Tools The Clone Stamp tool, the Healing Brush tool, the Spot Healing Brush. the algorithms Photoshop uses so that it applies a special blending that is better at preserving some high-frequency data, including details and noise. In many cases the For Photoshop Elements. Brush. Content-Aware Healing In CS5, the Spot Healing Brush has an option to set the Type as Content-Aware rather than Proximity or Texture. In earlier versions of Photoshop, nature photographers