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									                                                           Distorting for Fun              539

                                                                                   Corbis Digital Stock
Figure 2-6: Use the Straighten tool to fix the horizon line in the Lens Correction dialog box.

    Zigzag in                                      Glass in                                               Book VII
Pond Ripples mode       Normal        Wave      Frosted mode       Spherize                               Chapter 2

                                                                                                             Applying Filters for
                                                                                                             Special Occasions

Figure 2-7: A normal clock takes on Dali-esque qualities with various Distort filters.
540   Pumping Up the Noise

         The Glass filter can do the following to your images:

          ✓ Add a glass-block texture
          ✓ Add a canvas texture
          ✓ Create frosted-glass fuzziness
          ✓ Break up your image with tiny lenses

         Don’t like any of Photoshop’s textures? No biggie; you can also load your
         own texture. Click the Texture pop-up menu (the right-pointing arrow) and
         select Load Texture.

Pumping Up the Noise
         Noise in images consists of any graininess or texture that occurs, either because
         of the inherent quality of the image or through the editing process. Noise filters,
         such as the Photoshop Add Noise plug-in, produce random texture and grain in
         an image. If you’re new to image editing, you might wonder why you’d want to
         add noise to an image in the first place. Wouldn’t it be smarter to remove it?
         Well, sometimes. In practice, you can find a lot of applications, including the
         following, that call for a little noise here and there:

          ✓ Adding texture: Objects that become too smooth, either because of
            blurring or other image editing you may have done, often look better
            when you add some noise to give them a texture. This technique is par-
            ticularly useful if one object in an image has been edited, smoothed, or
            blurred more than the other objects in the image.
          ✓ Blending foreign objects into a scene: When you drop a new object into
            the middle of an existing scene, the amount of grain or noise in the new
            object is often quite different from the objects it’s joining.
             For example, say you’ve decided to take a photo of your house and want
             to insert a certain luxury car in your driveway. Unfortunately, your digi-
             tal photo of your brother-in-law’s luxo-mobile is a lot sharper than the
             picture of your house. Adding a little noise can help the two objects
             blend more realistically. You may even forget that the car isn’t yours.
          ✓ Improving image quality: Images that contain smooth gradients often
            don’t print well because some printers can’t reproduce the subtle blend
            of colors from one hue to another. The result is objectionable banding in
            your printed image: You can see distinct stripes where the colors prog-
            ress from one to another. Adding a little noise can break up the gradient
            enough that your printer can reproduce the blend of colors, and the
            noise/grain itself is virtually invisible on the printed sheet.
                                               Pumping Down the Noise            541

Pumping Down the Noise
      Although the Add Noise filter adds grain, the other filters in the Noise sub-
      menu don’t add noise at all; instead, they make noise and artifacts (flaws,
      such as the dust and scratches on old film) less noticeable. Choose Filter➪
      Noise to find your tools, which include

       ✓ Despeckle: This filter makes dust spots in your image less noticeable by
         decreasing the contrast of your entire image — except at the edges. That
         translates into a slightly blurry image (which masks the spots) that still
         retains sharpness along the edges of image components. You end up
         with a little blur to soften the image but enough detail in the edges that
         the picture still looks good.
       ✓ Dust & Scratches: This filter concentrates its blurring effect on only those
         areas of your image that contain scratches and other artifacts. Photoshop
         performs this magic by looking at each pixel in an image and moving out
         in a radial direction until it encounters an abrupt transition in tone.
         (That’s a signal that a spot or scratch has been found.) You can specify
         the radius in which Photoshop searches for the little culprits, from 1 to
         100 pixels. Be careful not to overdo it. Too much of this filter can obliter-
         ate the detail in the image. Leave the Threshold at 0. If you journey into
         the world of mush, try using Edit➪Fade right after you apply the filter.
                                                                                           Book VII
          When working with any of the Noise filters, be very conservative at first.       Chapter 2
          All the Noise filters involve destruction of image data. Remember, that’s
          just the nature of filters, in general — changing pixel data. A little bit can

                                                                                              Applying Filters for
                                                                                              Special Occasions
          help — and be just the effect you’re looking for. Just a little bit more,
          however, may completely wreck things.
       ✓ Median: This filter reduces contrast around dust motes, thus hiding
         them, in a slightly different way. This filter looks at the pixels surround-
         ing each pixel in the image and replaces the center one with a new pixel
         that has the median brightness level of that group. The process is a little
         hard to describe succinctly, but basically, the bright spots darken while
         the rest of the image isn’t affected. For more on the Median filter, see
         Book VII, Chapter 1.
       ✓ Reduce Noise: This filter, shown in Figure 2-8, is designed to remove
         luminance noise and JPEG artifacts that can appear on digital photos.
         Luminance noise is grayscale noise that makes images look overly
         grainy. Here’s some info on the options:
           • Strength: Specify the amount of noise reduction. You can reduce
             noise in the overall image or (if you click the Advanced button) chan-
             nel by channel.
             Be sure to check out the Blue channel, in particular. It’s often the
             channel that captures all the crud.
           • Preserve Details: A higher number preserves edges and details but
             reduces the amount of noise removal. Find a happy medium.
542   Breaking Your Image into Pieces

               • Reduce Color Noise: Removes random colored pixel artifacts.
               • Sharpen Details: Counteracts the fact that removing noise reduces
                 sharpness, as well.
               • Remove JPEG Artifact: Check this option to remove the annoying
                 blocks and halos that can occur because of low-quality JPEG
                  You can also save and reload your settings. Click the disk/arrow
                  icon. In the New Filter Settings dialog box, enter a name for your
                  settings and click OK. To load your settings, choose your desired
                  settings from the Settings drop-down list.

         Figure 2-8: The Reduce Noise filter attempts to remove noise while
         retaining some sharpness in edges and details.

Breaking Your Image into Pieces
         The Pixelate filters in Photoshop break your images into bits and pieces,
         providing more of those painterly effects you can get with brush strokes and
         artistic filters.

         The Pixelate submenu includes the Crystallize filter (applied to the little girl
         shown in Figure 2-9), as well as plug-ins that produce color halftone effects,
         fragmented images, and the pointillize effect (used in the “Creating Snow and
         Rain” Putting It Together project, in this chapter).
                                                                          Rendering         543

                                                                                    Corbis Digital Stock   Book VII
      Figure 2-9: The Crystallize filter breaks your image into polygonal shapes.                          Chapter 2

                                                                                                              Applying Filters for
                                                                                                              Special Occasions
      In computerese, rendering means creating something from nothing, in a way.
      That’s why all rendering filters in Photoshop produce special effects by cre-
      ating a look, object, or lighting effect that’s melded with your original image.

      Using the Clouds filter
      The Clouds filter can muster a sky full of clouds from scratch with a few clicks of
      the mouse, as in the now-cloudy picture shown in Figure 2-10. This filter creates
      clouds using random values from the foreground and background colors.
      Indeed, most Photoshop veterans use this filter so much that they have a sur-
      prising number of clouds in their images. Find it at Filter➪Render➪Clouds. To
      create a more contrasty cloud effect, hold down Alt (Option on the Mac) quickly
      when choosing the command. If you don’t like the first set of clouds you get,
      apply the filter again and again until you do. If you want a more “realistic” sky,
      try using a dark sky blue for your foreground color and a very light blue, or
      white, color for your background color. Be sure to apply the filter on its own
      layer, if you don’t want to obliterate the original contents of your image.
544   Rendering

                                                                    Brand X Pictures
         Figure 2-10: Got clouds? Make your own with the Clouds filter.

         Need a quick Web background image? Create a 128-x-128-pixel (or some mul-
         tiple of that size) image and apply the Clouds filter. It tiles seamlessly on
         your Web page.

         Creating fibers
         This filter can create a textilelike effect out of thin air. Choose Filter➪
         Render➪Fibers. In the dialog box that appears, move the Variance slider to
         increase the contrast between light and dark areas. Move the Strength slider
         to increase the tightness of the weave of the fibers. Click the Randomize
         button to get another variation of the effect of the filter.

         Using other rendering filters
         Other useful filters on the Render submenu (at Filter➪Render) include
                                                                          Rendering       545

       ✓ Difference Clouds: Use this filter to create puffy objects in the sky (or
         foggy clouds at lower levels). Instead of performing this magical feat the
         way the Clouds filter does, the Difference Clouds filter uses image infor-
         mation to figure the difference in pixel values between the new clouds
         and the image they’re joining. The result is a unique cloud effect. Try
         applying the filter repeatedly to create a marbleized effect.
       ✓ Lens Flare: This filter creates the reflection effect that plagues photogra-
         phers when they point their cameras toward a strong light source, such
         as the sun. Photoshop mimics several different kinds of photographic
         lenses, giving you useful flares that can spice up concert photos, add a
         sunset where none existed, and create other kinds of lighting bursts. In
         the Lens Flare dialog box, specify a location for the center of the flare by
         clicking the image thumbnail or dragging the crosshair.
       ✓ Lighting Effects: As a sort of photo-studio lighting setup, this filter uses
         pixels to do its work. You can set up 16 different lights and manipulate
         how they illuminate your photo.

Putting It Together

      Creating Snow and Rain
      Sometimes, you may come across a photo that needs a little bit of atmosphere thrown in     Book VII
      to give it extra punch. And I mean atmosphere literally. By using a couple of filters and   Chapter 2
      a blend mode, you can add some rain or snow to any image. Just follow these steps to

                                                                                                    Applying Filters for
                                                                                                    Special Occasions
      create either rain or snow:

      1.   Open a color image. If it isn’t currently
           in RGB mode, choose Image➪Mode➪
           RGB Color.
           Make sure you’re in RGB mode; the
           blend mode used in these steps
           doesn’t work correctly with CMYK
      2.   Drag the background layer to the
           Create a new layer icon at the bottom
           of the Layers panel.
           You now see a layer named
           Background Copy in the Layers panel.
      3.   Double-click the name Background Copy and type Snow.
           This isn’t a mandatory step. I’m just being ultra-organized.
546   Rendering

         4.   First, set your background color to
              white. With the Snow layer active,
              choose Filter➪Pixelate➪Pointillize.
              In the dialog box, set your cell size to
              whatever value you prefer. Click OK.
              The bigger the cell size, the bigger the
              snowflakes or raindrops.
              For rain, you might try a cell size of 3
              (which is the minimum) or 4. For snow,
              try a larger cell size, between 6 and 9.
              I used a value of 7 in my image.
         5.   On the Snow layer, choose Image➪Adjustments➪Threshold. Move the slider all
              the way to the right, to a max value of 255.
              This adjustment takes the colored cells and turns them to either black or white.
              By using a value of 255, all brightness values less than 255 turn black, and the
              remaining value turns white.
         6.   On the Snow layer, select Screen from
              the Mode pop-up menu in the Layers
              The Screen blend mode lightens
              the Snow layer, where it mixes with
              the background. Blending with black
              pixels has no effect; therefore,
              they drop out, as shown in the
         7.   Choose Filter➪Blur➪Motion Blur. In
              the dialog box that opens, specify the
              Angle and Distance values.
              If you want the wind to appear to be
              blowing hard, set the angle more diag-
              onally, around 45 degrees. If you want
              the precipitation to appear to be
              coming straight down, set the angle to
              90 degrees. Setting the distance elon-
              gates the pointillized cells that you
              created in Step 4, making them look a
              little more realistic. For snow, start
              with a range of about 8 to 12 pixels. For
              rain, start a little higher, around 15 to
              25 pixels. I used a value of 12 pixels in
              my figure.
                                    Getting Organic with the Sketch Filters                   547

            If you’re creating rain, proceed to Step 8. If you’re a snow person, you’re done, as
            shown in the figure.
       8.   Choose Filter➪Sharpen➪Unsharp Mask.
            The Unsharp Mask dialog box appears.
       9.   Specify the Amount, Radius, and Threshold values and click OK.
            The Unsharp Mask filter gives the illusion of sharpening the focus of the image by
            increasing the contrast between the pixels.
            I used an amount of 500%, a Radius of 1, and kept the Threshold at 0. This gives the
            raindrops a little more definition.
      10.   Choose Filter➪Blur➪Motion Blur. In
            the dialog box that appears, specify
            the Angle and Distance values.
            Again, the angle is up to you, but make
            it consistent with the value that you
            used in Step 7. Set the distance
            according to how you want your rain
            to appear — a moderate spring rain or
            a torrential, close-to-hurricane type of
            downpour. In the image shown here, I
            used 45 degrees and 25 pixels.                                                          Book VII
                                                                                                    Chapter 2

                                                                                                       Applying Filters for
                                                                                                       Special Occasions
Getting Organic with the Sketch Filters
       The Sketch filter submenu contains a few filters that don’t really belong
       there. That’s because many current Photoshop filters were acquired from
       Aldus Corporation (now defunct), and Adobe had to shoehorn them into
       the organizational structure of Photoshop. But no matter — they work

       If you were to encounter a picture of Michelangelo’s David, shown in
       Figure 2-11, you might be tempted to sketch the famous sculpture by
       using one of the filters you can find when you choose Filter➪Sketch.

       Perhaps a Conté Crayon effect or a Graphic Pen and Ink look would be nice.
       But the Sketch submenu also includes other artistic effects, such as the Note
       Paper look, a halftone screen, chalk and charcoal, and even a bas-relief effect
       that turns flat images into a Michelangelo-esque sculpture.
548   Getting Organic with the Sketch Filters

                    Normal                        Conté Crayon

                  Graphic pen                      Note Paper

                                                           Corbis Digital Stock
         Figure 2-11: Give your digital photos a more organic feel with
         the Sketch filters.

         You can also experiment with these other Sketch filters:

          ✓ Chrome: Creates a polished chrome effect. Use the Levels adjustment to
            add more contrast, if necessary.
          ✓ Photocopy: Gives that infamous, anachronistic look (dating back to the
            days when photocopiers didn’t do a very good job of reproducing half-
            tone images). Creates areas of black and white with little gray value
            when the default foreground and background colors of black and white
            are selected.

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