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									      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
                                                                     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
             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
       ✓ 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.

         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
 ✓ 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
          ✓ 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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