Document Sample
					                                                 Using Simple Color Correctors                 589

Putting It Together

      Correcting Tinted, Faded Photos
      In this Putting It Together project, I employ the Variations feature to restore the color in a
      scan of a color print originally made in 1965. Unfortunately, the years have not been kind
      to this photo; it has a slight, but annoying, greenish tinge because the magenta dye layer
      of the print has faded. As a result, the other two color layers, cyan and yellow, appear
      proportionately stronger when compared to the magenta that remains, and cyan and
      yellow make a shade of green.

      I plan to use the Variations feature of Photoshop to restore the magenta layer in this
      photo that’s green with age.

      To correct colorcast in an old photograph by using the Photoshop Variations feature,
      follow these steps:

      1.   In Photoshop, open an old, fading photo that needs color correction.
           In this case, I’m using an old, faded, greenish-looking picture, shown in the figure,
           but any colorcast works.

                                                                                                       Book VIII
                                                                                                       Chapter 1
                                                                                                          Enhancing Images
                                                                                                          with Adjustments

590   Using Simple Color Correctors

          2.   Choose Image➪Adjustments➪Variations from the menu bar.
               The Variations dialog box appears.
          3.   Select the Show Clipping option to tell Photoshop to show any areas of the image
               that will be “overwhelmed” by the correction you’re contemplating.
               That is, no new information is added.
          4.   If you want to use corrections you saved, load those settings by clicking the Load
               button. Otherwise, skip to Step 5.
          5.   Make adjustments with the Fine/Coarse slider.
               In my example, the greenish picture needs some magenta, so I dragged the Fine/
               Coarse slider to the left. I wanted to have a smaller increment of change when I
               adjusted the color.
               You can also click one of the tick marks to move the slider to that position.
               Photoshop doesn’t allow setting the control to any of the intermediate positions
               between the marks.
          6.   Make sure that you’ve selected the Midtones radio button, and then click the
               Preview window containing the amount of color you want to add.
               Watch the Current Pick thumbnail, which reflects the correction.
               In my case, I need to click the More Magenta image.
               Click several times if your initial application isn’t enough or click other Preview win-
               dows to add additional colors.
               Photoshop applies your corrections only to the middle tones of the image. In many
               cases, that’s sufficient. However, sometimes shadows take on a particular hue, or
               the highlights may gain colorcasts of their own.
          7.   Click the Highlights and/or Shadows radio buttons to add colors only to those parts
               of the photo.
               Variations isn’t the best tool to make complex color corrections, so be careful.
               You might be able to see a highlight color in the shadows under the pillow, most
               noticeable in the More Magenta preview. The highlight is the Clipping indicator
               showing that the change made by that Preview window is too much for that particu-
               lar area of the picture. That is, Photoshop can’t add any more magenta to the high-
               lighted area without losing detail in the image.
                                           Using Simple Color Correctors               591

 8.   Click the Darker preview (in the lower-right corner of the dialog box) to make the
      photo a little darker.
      Adjust the Fine/Coarse slider to adjust the amount of change, or gradually darken
      and lighten the image by clicking multiple times.
      In my case, only one click is necessary.
 9.   Click the Saturation radio button to brighten the colors and use the Fine/Coarse
      slider to control how much saturation you add or remove.
      The Variations feature also lets you adjust the purity of color, or saturation, of the
      colors in an image. Now, only three previews appear: a less-saturated version, the       Book VIII
                                                                                               Chapter 1
      current choice, and a more-saturated version. My photo was washed out, or under-
      saturated, so I clicked the More Saturation button.                                         Enhancing Images
                                                                                                  with Adjustments

10.   To save your settings, click the Save button, apply a name to the settings, and store
      them in the folder of your choice.
592   Working with Professional Color Correctors

              I recommend saving your settings, especially if you’re working on a copy of the
              original image and want to apply the same corrections later, or if you plan to correct
              several photos that have the same color defects.

Working with Professional Color Correctors
         The simple color correctors I discuss in the section “Using Simple Color
         Correctors,” earlier in this chapter, usually aren’t enough to provide thor-
         ough color correction if you have a really problematic image on your hands.
         Fortunately, Photoshop has the kind of professional tools needed to make
         sophisticated color corrections for higher-end color printing. You don’t
         have to be a pro to use the Levels or Curves commands, nor to work with
         the Hue/Saturation controls. But you’ll feel like one after you master these
         powerful tools.

         Leveling for better contrast
         If you want to adjust tonal values of images (the brightness or darkness of
         tones) or correct colors (the relationship between the colors), the Levels
         command is the tool for you. It offers more control than the Auto Tone com-
         mand, which I discuss in the section “Auto Tone,” earlier in this chapter. The
                     Working with Professional Color Correctors                 593

Levels command is also a much more sophisticated tool than the Brightness/
Contrast control because you can work with individual tones, brightening or
darkening individual tones as you want, and you have a great deal more infor-
mation to help you make your choices.

Open the Levels dialog box, shown
in Figure 1-13, by pressing Ctrl+L
(Ô+L on the Mac) or choosing Image➪
Adjustments➪Levels. The graph shown
in the center of the dialog box is a his-
togram, which I describe in detail in
the section “Introducing the Histogram
Panel,” earlier in this chapter. You can
use this dialog box, histogram and all,
for evaluating and adjusting levels in
the following ways:

 ✓ Visually check the distribution of
   dark, midtone, and light values.
                                             Figure 1-13: The Levels dialog box offers
 ✓ View separate histograms for           controls for adjusting the contrast in your
   each channel. The default histo-       image.
   gram displays information for the
   entire image. To see the histogram
   of an individual channel, select it from the Channel pop-up menu. For an
   RGB image, you can view the Red, Green, and Blue channels. For a CMYK
   image, you can view the Cyan, Magenta, Yellow, and Black channels. You
   can view the histograms of each channel simultaneously by using the
   Histogram panel.
 ✓ Adjust the black and white points based on the histogram. The three
   triangles at the bottom of the histogram, in black, gray, and white, rep-
   resent the shadow on the left, midtone in the middle, and highlight on
   the right. Even though they’re located where they are, many images
   have no black tones at the far-left side of the scale nor white tones at
   the far-right side.                                                                   Book VIII
                                                                                         Chapter 1
    One of the simplest corrections you can do is to move the black and
    white sliders so that they actually correspond to the pixels containing                 Enhancing Images
                                                                                            with Adjustments

    dark and light tones. Simply slide the black triangle so that it corre-
    sponds to the first true black pixels in the image (the beginning of the
    histogram), and then move the white triangle to align it with the lightest
    pixels (the end of the histogram). That ensures that Photoshop doesn’t
    waste tones by allocating them to areas of the image that actually have
    no image detail. Figure 1-14 shows an example of an image that was res-
    cued by the use of the Levels adjustment.
594   Working with Professional Color Correctors

         Figure 1-14: Applying the Levels command to a dark photo dramatically improves the

          ✓ See exactly what happens when you use the Auto Tone command.
            When you click the Auto button, which applies the same adjustments as
            the Auto Tone command, Photoshop applies its own suggested changes,
            resetting the white point and the black point, and redistributing the gray
            values of the pixels in between. Afterward, the histogram shows that the
            pixels fill the complete range from white to black.

         Setting black and white points manually
         For more control, you can use the Eyedropper tools in the Levels dialog box
         to set the black and white points. Just follow these steps:

          1. Open an image and choose Image➪Adjustments➪Levels.
             Make sure you have the Info panel open (Window➪Info), and display the
             HSB and RGB color modes. (To do this, select Panel Options from the
             Info panel pop-up menu and select HSB and RGB from the Color Readout
             pop-up menus.) See Book II, Chapters 2 and 3 for more on color modes.
             Remember that you can also apply certain adjustments, such as Levels, via
             an adjustment layer rather than directly to the image itself. Adjustment lay-
             ers provide more editing flexibility if you later decide you need to tweak
             the adjustment. For more on adjustment layers, see Book V, Chapter 1.
          2. Select the White Eyedropper tool and move it around the image while
             watching the Info panel.
          3. Look for the lightest white in the image, which may be anywhere from
             90% to 100% in brightness (the B under HSB). Select that point by
          4. Using the Black Eyedropper tool, repeat the process outlined in Steps
             2 and 3 to select the darkest black in the image, which may be any-
             where from 0% to 10% in brightness (B).
             The combination of these two choices redistributes the pixels from pure
             white to pure black.
                   Working with Professional Color Correctors            595

   You can also set the white and black points by moving the position of
   the white and black triangles on the input sliders (just under the histo-
   gram). Or you can enter numbers in the Input Levels boxes. The three
   boxes represent the black, gray, and white triangles, respectively. Use
   the numbers 0 to 255 in the white and black boxes.
5. Use the Gray Eyedropper tool to remove any colorcasts. Select an area
   of your image that should be neutral gray, one in which the Info panel
   shows equal values of red, green, and blue.
   Note that the Gray Eyedropper tool isn’t available when you’re working on
   grayscale images.
   Although you generally make changes to the entire document by using
   the RGB channel, you can apply changes to any one of an image’s com-
   ponent color channels by selecting the specific channel in the Channel
   pop-up menu at the top of the Levels dialog box. (Refer to Figure 1-13.)
   You can also make adjustments to selected areas only. This can be help-
   ful when one area of your image needs adjusting but others don’t. See
   Book III, Chapter 1 for details on making selections.
6. Adjust the output sliders at the very bottom of the Levels dialog box.
   Moving the black triangle to the right reduces the contrast in the shad-
   ows and lightens the image. Moving the white triangle to the left reduces
   the contrast in the highlights and darkens the image.
7. Adjust the midtones with the gray triangle slider. (It appears between
   the black and white input sliders, just under the histogram.)
   The values you’re adjusting are called the gamma values.
   Dragging this triangle to the left lightens the midtones. Dragging it to the
   right darkens the midtones while leaving the highlights and shadows
   alone. You can also move the gray triangle by entering numbers from
   9.99 to 0.1 in the center option box. The default value (1.0) lies exactly in
   the middle of the range.
   If you’re working with a series of similar images (such as a bunch of
   video captures), you can save the settings to reuse them later.                 Book VIII
                                                                                   Chapter 1
   You can also select a preset Levels setting, such as Increase Contrast or
   Lighten Shadows, from the Preset pop-up menu in the Levels dialog box.
                                                                                      Enhancing Images
                                                                                      with Adjustments

   Use a preset as your starting point and then fine-tune the adjustment
   manually by adjusting the input sliders, as described in the preceding
8. Click the Save button to store your settings.
   This step saves the settings, but it doesn’t apply them. Just click the
   Load button to retrieve them.
9. Click OK to apply your settings and exit the dialog box.
596   Working with Professional Color Correctors

         Adjusting curves for hard-to-correct photos
         The Curves command is one of the most advanced Photoshop correction
         tools available, offering sophisticated control over the brightness, contrast,
         and midtone (gamma) levels in an image; I’m talking about control that’s far
         beyond what the Levels and Brightness/Contrast dialog boxes offer. This
         section introduces you to the functions of the Curves command, but you’ll
         want to practice using it a great deal to gain the kind of experience you need
         to work with it effectively.

         Whereas the Brightness/Contrast dialog box lets you change an image glob-
         ally, and the Levels command allows you to change the shadows, highlights,
         and midtones separately, Curves goes far beyond either of those settings. It
         lets you change pixel values at 16 different points (which include start and
         end points) along an image’s tonal range. You can work with the combined
         Red, Green, and Blue color channels (or CMYK channels) or apply your
         changes to the individual colors. Often, images that just can’t be fixed to
         your satisfaction with Levels can be helped with the Curves adjustment, as
         shown in Figure 1-15.

                                                                                   PhotoDisc/Getty Images

         Figure 1-15: The Curves adjustment offers more control and sophistication than many other
         color correction tools.
                    Working with Professional Color Correctors                 597

Working with the Curves dialog box
You access the Curves dialog box, shown in Figure 1-16, by choosing
Image➪Adjustments➪Curves or by pressing Ctrl+M (Ô+M on the Mac).

The following tips help you to begin understanding how to interpret the
information and use the tools in this dialog box:

 ✓ The horizontal axis maps the brightness values as they are before
   image correction (input).
 ✓ The vertical axis maps the brightness values after correction (output).
   Each axis represents a continuum of 256 levels, divided into four parts
   by finely dotted lines. In the default mode, the lower-left corner repre-
   sents 0,0 (pure black) and the upper-right corner is 255,255 (pure white).
   By default, the dialog box shows a 4-x-4 (quarter tone) grid; Alt-click
   (Option-click on the Mac) inside the grid to toggle it to a 10-x-10 (10%
   increment) grid. If you have the Curve Display Options visible, you can
   use the Quarter Tone or 10% Increment display buttons.
 ✓ Whenever you open the                Adjust curve by adding points
   Curves dialog box, the graph
   begins as a straight line. Unless         Draw curve        Highlights
   you make changes, the input is                      Midtones          Save/Load Preset
   exactly the same as the output,
   a direct 1-to-1 correlation.
 ✓ You can expand the Curve
   Display Options and specify
   the following:
     • Show Amount Of: Choose
       between Light and Pigment
       to display the brightness
       levels or percentages. To
       keep things simple, I’d leave
       them at the default of Light
       (levels), where darker values                                                        Book VIII
       are at the bottom-left and                                                           Chapter 1
       lighter values are at the top-                                                          Enhancing Images
                                                                                               with Adjustments

       right. Choose between a sim-
       ple or detailed grid (icons).
     • Show: If you’re adjusting               Black and White Point sliders
       curves for individual chan-
       nels, choose Channel
       Overlays to superimpose          Figure 1-16: The Curves dialog box offers
       those individual curves.         maximum control for adjustment of your
                                        image’s color and tones.
598   Working with Professional Color Correctors

                Select Baseline to show your original straight line curve. Choose to
                display a histogram overlay. For more on histograms, see the section
                “Introducing the Histogram Panel,” earlier in this chapter. Select
                Intersection Line to display horizontal and vertical lines to help you
                align your points while you drag them on the curve.
          ✓ The Eyedropper can show you pixel values. When you use the
            Eyedropper tool to click in the image, a circle appears on the graph to
            show you the value of the pixel being sampled. At the bottom of the
            Curves grid box, you can read the pixel’s input and output values.
          ✓ Auto sets black and white values. When you click the Auto button, the
            darkest pixels in the image (the deep shadows) are reset to black, and
            the lightest areas are set to white. Like with the Levels dialog box, this
            option is the easiest way to make a correction but may not be the best.
          ✓ Eyedropper tools can also set black, white, and gray values. The Curves
            dialog box has black, white, and gray Eyedropper tools you can use to set
            the black, white, and midtone points, just like you can with Levels.
          ✓ Select the Show Clipping options to have Photoshop display where
            clipping occurs in the image during your corrections. Remember, clip-
            ping occurs when a pixel’s values are lighter or darker than the highest
            or lowest value that can be displayed in the image, resulting in loss of
            detail in those areas.

         Adjusting curves
         If you click at any point on the curve other than the end points, Photoshop
         adds a control point that shows your position. You can remove a control
         point by dragging it downward until it’s completely off the graph or by drag-
         ging it on top of the next point up or down from it on the graph. You can add
         up to 14 points to the curve.

         Curve presets are located at the very top of the Curves dialog box. If you’re a
         Curves novice, trying one of these presets is a good way to get your feet wet
         in how curves work. Note that when you select a preset, a curve is loaded
         into your dialog box. You can also use a preset as a starting point and then
         tweak it further with your own adjustments. Experiment with the curves to
         see how they affect the image. For example:

          ✓ Click the Auto button to have Photoshop analyze your image’s color and
            tonal values and make an automatic adjustment. Again, you can use this
            preset as a starting point and tweak from there.
          ✓ Flattening a curve lowers contrast.
          ✓ Making a curve steeper heightens contrast.
          ✓ Moving a curve downward (if the display is set to Light) darkens the
            image. Moving it upward lightens.

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