Chapter 1: Making Corrections with Daily Filters In This Chapter ✓ Understanding how filters work ✓ Introducing Smart Filters ✓ Sharpening soft areas ✓ Improving an image with blurring ✓ Smoothing defects with Median and Facet filters ✓ Fading a filter’s effects ✓ Applying filters repeatedly or selectively F ilters have a long and glorious history, ranging from performing essen- tial tasks (such as removing abrasive particles from the oil in your car’s crankcase) to even more important chores involving the pixels in your Photoshop images. In both cases, filters (also called plug-ins because they can be installed or removed from Photoshop independently) seize tiny, almost invisible bits of stuff and rearrange them in useful ways. The results are something you’d never want to do without. This chapter introduces you to the basics of Photoshop’s filter facilities and starts you on the road to plug-in proficiency. You Say You Want a Convolution? All filters do one simple thing in a seemingly compli- cated way: They make Photoshop do your bidding. Deep within a filter’s innards is a set of instructions that tells Photoshop what to do with a particular pixel in an image or selection. Photoshop applies these instructions to each pixel in the relevant area by using a process the techies call convolution (creating a form or shape that’s folded or curved in tortuous windings), but which we normal folk simply refer to as applying a filter. 510 You Say You Want a Convolution? Corrective and destructive filters Filters fall into two basic categories: ✓ Corrective filters: Fix problems in an image. They fine-tune color, add blur, improve sharpness, or remove such nastiness as dust and scratches. Although corrective plug-ins can be fairly destructive to cer- tain pixels, they don’t change the basic look of an image in general. You might not even notice that a corrective filter has been applied unless you compare the new version of the image with the original. ✓ Destructive filters: Tend to obliterate at least some of an image’s origi- nal detail (some to a greater extent than others) while they add special effects. They may overlay an image with an interesting texture, move pixels around to create brush strokes, or distort an image with twists, waves, or zigzags. You can often tell at a glance that a destructive filter has been applied to an image: The special effect often looks like nothing that exists in real life. An unaltered image (such as the image on the left in Figure 1-1) can be improved by using a corrective filter such as Unsharp Mask (center) or changed dramatically with a destructive filter such as Find Edges (right). Corbis Digital Stock Figure 1-1: Filters range in variety from the corrective (center) to the destructive (right). Filter basics Whether a filter is corrective or destructive, it falls into one of two camps. Here’s the scoop: ✓ Single-step filters: The easiest filters to use, single-step filters have no options and use no dialog boxes. Just select the filter from the menu and watch it do its stuff on your image or selection. The basic Blur and Sharpen filters are single-step filters. Introducing Smart Filters 511 ✓ Mini-application filters: Most filters come complete with at least one dialog box, along with (perhaps) a few lists, buttons, and check boxes. And almost every mini-app filter has sliders you can use to adjust the intensity of an effect or parame- ter. (See Figure 1-2.) These filters are marked in the menus with an ellipsis (a series of dots) following their names; like with other menu commands that show those dots, it’s an indication that you’re about to be presented with a dialog box where more options are lurking. The controls themselves are easy to master. The tricky part is figuring out what the various parameters you’re using actually do. How does changing Figure 1-2: Mini-application filters require brush size affect your image when you to specify various settings before you’re using a brush-stroke filter? What applying your filter. happens when you select a particular pattern with a texturizing filter? You can read descriptions of how various Book VII filter controls affect your image, but your best bet is to simply experiment Chapter 1 until you discover the effects and parameters that work best for you. Just be Making Corrections with Daily Filters sure that you save a copy of the original image; filters do permanent damage to files — modifying, adding, and deleting pixels. Adobe also provides a command under the Filter menu — Browse Filters Online. Selecting this command launches your browser and takes you to the Photoshop Marketplace, where you’ll find lots of downloadable Photoshop goodies — filters, brushes, shapes, patterns, actions, user groups, work- shops, and so on. Introducing Smart Filters In my humble opinion, Smart Filters is one of the best recent features of Photoshop. Smart Filters are the same filters we all know and love, but they are applied to your image nondestructively. Technically, the filters are applied to your pixel data, but Photoshop always retains the original pixel data inside the Smart Object. Then, each time a filter is edited, Photoshop installs the original pixel data and reapplies the filter. Never mind how it’s done behind the curtain; just know that Smart Filters act like layer effects, appending themselves to your layer, where they can be edited, rearranged, and deleted at any time. For more on Smart Objects, see Book V, Chapter 5. 512 Introducing Smart Filters Here are the steps to apply a Smart Filter: 1. Create a Smart Object by doing one of the following: • Choose File➪Open as Smart Object. Select your file and click Open. • In an existing file, choose File➪Place. Select your file size and posi- tion the image to your liking, and press the Commit button in the Options bar in Photoshop. • Select a layer in the Layers panel and choose Layer➪Smart Objects➪ Convert to Smart Object. • Select a layer in the Layers panel and choose Filter➪Convert for Smart Filters. • Copy and paste Illustrator content as a Smart Object into Photoshop. 2. Select your desired filter from the Filter menu. Any filter applied to a Smart Object becomes a Smart Filter. Your Smart Filter is appended beneath your Smart Object layer, as shown in Figure 1-3. Corbis Digital Stock Figure 1-3: Apply Smart Filters for nondestructive effects. Introducing Smart Filters 513 You can also apply the Shadows/ Filter Mask Highlights and Variations adjust- ments as Smart Filters. These are found under the Image➪ Adjustments submenu. When you add a Smart Filter to a layer, Photoshop automatically adds a layer mask. Technically, when a layer mask is applied to a Smart Filter, it’s called a filter mask. Correspondingly, an alpha channel appears in the Channels panel, as shown in Figure 1-4. By default, the entire filter is dis- played, as evidenced by an all-white filter mask. But the application of a filter mask enables you to selec- tively hide and show the effects of the filter, shown in Figure 1-4, where I applied the filter to the background (as indicated by the white in the filter mask) but not to the sea lion (as indicated by the Book VII Chapter 1 black in the filter mask). If you made a selection on the layer Making Corrections with Daily Filters before applying a Smart Filter, the mask will reflect that selection. For more Smart Filter masking details, see the following bulleted list. For information on masking in general, check out Book VI. Note that the Masks panel enables you to control and fine-tune masks of all types, including layer masks, vector masks, and filter masks. Check out Book VI, Chapter 3 to find out details on using this great panel. Alpha channel 3. Edit the filter as often as you like by simply double-clicking the Figure 1-4: Smart Filters come equipped filter name in the Layers panel. with their own mask. You can also right-click (Control- click on the Mac) the filter name to access a context menu from which you can select Edit Smart Filter. (Refer to Figure 1-3.) 514 Introducing Smart Filters Your filter’s dialog box appears, enabling you to adjust the parameters, as desired. You can’t edit single-step filters (those that don’t display a dialog box but are automatically applied). You can, however, double- click to reapply certain filters, such as Clouds and Difference Clouds, that reside in the Render filter submenu. 4. (Optional) If desired, adjust the blend modes and opacity settings of the Smart Filter by right-clicking (Control-clicking on the Mac) on the filter line in the Layers panel to access a context menu. From that menu, select Edit Smart Filter Blending Options. In the dialog box that appears, select your desired blend mode from the Mode pop-up menu. Adjust your opacity by entering a percentage or moving the slider. This is a great way to tone down the effect of the filter and achieve a more subtle appearance. Doing so is similar to fading a fil- ter (described in the section “Fading a Filter,” later in this chapter), only better because you can infinitely edit the settings. 5. Add as many filters as you need to the Smart Object. Filters reside in a grouped stack. 6. (Optional) If you no longer want the filter, delete it by selecting it in the Layers panel and dragging it into the trash at the bottom of the panel. To delete an entire Smart Filter group (multiple filters), grab the Smart Filters line in the Layers panel and drag it into the trash. You can also delete the filters by right-clicking (Control-clicking on the Mac) the filter name and selecting Delete Smart Filter from the context menu that appears. You can also delete all filters by right-clicking (Control-clicking on the Mac) the Smart Filters line in the Layers panel and choosing Clear Smart Filters from the context menu. Here’s everything else you need to know about the ins and outs of working with Smart Filters: ✓ Any file format that supports layers, such as PSD, TIFF, and PDF, supports Smart Filters. ✓ You can’t apply Liquify or Vanishing Point as Smart Filters. ✓ Click the eye icon next to the filter name in the Layers panel to display or hide the individual Smart Filter. Click the eye of the Smart Filters group to toggle on or off all the filters. ✓ When executing commands, such as a transformation (scale, rotate, and so on), on a layer that has a Smart Filter, Photoshop alerts you that it’ll turn off the Smart Filter in the preview during the transformation and reapply it after the transformation is complete. You may select the Do Not Show Again option to bypass the alert box from then on. Sharpening What’s Soft 515 ✓ You can rearrange the order of multiple filters by dragging them up or down the list in the Layers panel. ✓ To move a smart filter, drag the filter from one Smart Object layer to another. To copy Smart Filters, hold down Alt (Option on the Mac) while dragging. ✓ In the cases of multiple filters, only a single filter mask is applied to all filters within the group. ✓ You can use most of the same tools used to edit regular layer masks, such as the Brush and Gradient tools, to edit filter masks. ✓ You can adjust the Density and Feather options of the filter mask by using the Masks panel. See Book VI, Chapter 3 for details. ✓ Filter masks aren’t linked to the Smart Objects, so if you move either one with the Move tool, the other doesn’t move along with it. ✓ To hide the filter mask, hold down Shift and click the filter mask thumb- nail in the Layers panel. You can right-click (Control-click on the Mac) the filter mask thumbnail and select Disable Filter mask from the context menu that appears. ✓ To delete the filter mask, drag the thumbnail to the trash at the bottom of the Layers panel. You can also right-click (Control-click on the Mac) on the filter mask thumbnail and select Delete Filter Mask from the con- Book VII text menu that appears. In addition, you can also add, subtract, or inter- Chapter 1 sect the mask as a selection in this same context menu. Making Corrections ✓ To display just the filter mask, hold down Alt (Option on the Mac) and with Daily Filters click the filter mask thumbnail in the Layers panel. ✓ To add a filter mask, right-click (Control-click on the Mac) the Smart Filter line in the Layers panel and select Add Filter Mask from the con- text menu that appears. Sometimes, when converting from one color mode to another, such as when going from RGB to CMYK, certain filters can’t be supported. Photoshop prompts you with an alert box saying so and asks you whether you want to rasterize the layer. Rasterizing essentially converts your Smart Object into a regular layer and fuses your Smart Filters onto that layer. Bye-bye, Smart Filter. If you choose not to rasterize, any Smart Filters that can’t be dis- played are annotated with an alert icon (a triangle with an exclamation mark) in the Layers panel. Sharpening What’s Soft Sometimes, your images aren’t as sharp as you want. Sometimes, your images have a tiny bit of softening caused by scanning an image or perhaps by capturing a photo on your digital camera. Or perhaps you want only a particular part to be sharper so that it stands out from its surroundings. 516 Sharpening What’s Soft All sharpening tools operate by increasing the contrast between adjacent pixels. If you look at a sharpened image side by side with the original version (as shown in Figure 1-5), you see that no new information has been provided. Instead, the contrast is boosted so edges are more distinct. The dark parts of the edges are darker; the light parts at their boundaries are lighter. Photoshop has six main sharpening features, only five of which are actually filters, on the Filter➪Sharpen menu. The sixth (the Sharpen tool) isn’t a fil- ter, strictly speaking. It is a tool in the Tools panel and is more like a paint- brush that lets you sharpen areas selectively by using strokes. Figure 1-5: Sharpening an image boosts the contrast of neighboring pixels and gives the illusion of improved focus. Sharpen The Sharpen filter is best used for minimal touchups in small areas. This sin- gle-step filter increases the contrast between all the pixels in the image or selection. Although this filter makes the image look sharper, it can add a grainy look to solid areas that aren’t part of the edges. Sharpen More The Sharpen More filter, a single-step filter, increases the contrast between pixels even more than the regular Sharpen filter. Like the Sharpen filter, Sharpen More is best relegated to noncritical sharpening because it doesn’t do a very good job of sharpening large areas. Also, it doesn’t provide the control you need for more intense projects. Sharpening What’s Soft 517 Sharpen Edges The Sharpen Edges filter is a single-step filter that’s superior to the Sharpen and Sharpen More filters because it concentrates its efforts on the edges of images, adding sharpness without making the image grainy or noisy. It’s best used for quickie fixes. Smart Sharpen The newest member of the Sharpen team is definitely a keeper: Smart Sharpen does a great job of detecting edges and sharpening them less destructively. Like the veteran Unsharp Mask filter, discussed in the next section, this filter gives you a lot of control over the sharpening settings, as shown in Figure 1-6. Here’s the scoop on those settings: Book VII Chapter 1 Making Corrections with Daily Filters Corbis Digital Stock Figure 1-6: The Smart Sharpen filter gives the most control over your sharpening specifications. ✓ Preview: Obviously, keep this option selected so that you can take a gander at what’s happening as you sharpen. You’ll appreciate the large preview. ✓ Basic and Advanced: The only difference between the two views is that with the Advanced view, you can control the amount of sharpening in the Shadow and Highlight areas of your image. Use the following con- trols to fine-tune the amount of sharpening in your light and dark areas: • Fade Amount: Determine the amount of sharpening. • Tonal Width: Specify the range of tones you want to sharpen. Move your slider to the right to sharpen only the darker of the shadow areas and the lighter of the highlight areas. 518 Sharpening What’s Soft • Radius: Specify the amount of space around a pixel that’s used to determine whether a pixel is in the shadow or the highlight area. Move your slider to the right to specify a greater area. ✓ Settings: You can save your sharpening settings so that you can load them for later use without having to re-create them. Click the disk/ down-pointing arrow icon to do so. ✓ Amount: Use this control to vary the amount of edge sharpening. A higher value increases the contrast between pixels around the edges. Your choices range from 1 percent to 500 percent. For subtle amounts of sharpening, anything around 100 percent or less provides the effect you’re looking for without making the image appear overly contrasty (yes, that’s a technical term) or unrealistic. ✓ Radius: This slider controls the width (in pixels) of the edges that the fil- ter will modify. The higher the value, the wider the edge that’s affected. Your range varies from 0.1 pixel (for fine control) to 64 pixels (for broader sharpening effects). How you use this control varies chiefly on the resolution of your original image. Low-resolution images (100 pixels per inch and lower) look best when you use only a small radius value, from a fraction of a pixel up to 3 or 4 pixels. A good rule to consider when you select a radius is to divide your image’s ppi resolution by 150 and then adjust from there. For example, if you have a 150 ppi image, set the radius at 1 and then tweak from there. ✓ Remove: Specify the algorithm to be used to remove the blurriness in the image. Gaussian Blur is the method used by Unsharp Mask and is good for removing that hazy type of blurriness. Lens Blur detects and sharpens the edges and detail in the image, and it does a good job of reducing those nasty halos that can occur from sharpening. Motion Blur reduces the blur- riness that can occur when you move your camera (or your subject moves). ✓ Angle: Specify the direction of motion if you choose Motion Blur as your algorithm. ✓ More Accurate: Check this option to make Photoshop provide a more accurate removal of blurriness. It takes longer, but it’s worth the wait, as shown in Figure 1-7. Corbis Digital Stock Figure 1-7: Smart Sharpen can take your soft, mushy photo and make it come to life.
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