Publishers of technology books, eBooks, and videos for creative people

Home > Articles

  • Print
  • + Share This
This chapter is from the book

Changing Color Modes

Before converting your file to a different color mode, it's a good idea to save a "master" version of your photo first. That way, no matter what changes you make to your image, you always have the original, unaltered version.

To convert an image to grayscale:

  1. From the Image menu, select Mode > Grayscale ( Figure 3.5 ).

    Figure 3.5 Choose Image > Mode > Grayscale to convert an RGB image to grayscale. A grayscale image is only about 1/3 the size of an RGB image.

    A message appears asking "Discard color information?"
  2. Click OK ( Figure 3.6 ).

    Figure 3.6 To convert from RGB to grayscale, you will discard the color information. Before you convert an image to grayscale, you may want to save a separate version to preserve the colors in the original image file.

    The conversion discards all color information, resulting in an image with up to 256 shades of gray. (See the color plate section of this book for a full-color example.)

To convert an image to bitmap:

  1. From the Image menu, select Mode > Bitmap ( Figure 3.7 ).

    Figure 3.7 Choose Image > Mode > Bitmap to convert an image to Bitmap (black and white) mode.

  2. Click OK in the message box that appears, to first convert the image to grayscale ( Figure 3.8 ).

    Figure 3.8 Before converting to Bitmap mode, your image is converted to grayscale.

    The Bitmap dialog box appears ( Figure 3.9 ).

    Figure 3.9 The Bitmap dialog box.

  3. If desired, enter a value for the output resolution. The default value is the current resolution of the image, which is usually fine for most purposes, and need not be changed during this conversion.
  4. From the Use drop-down menu, choose from one of the following three conversion methods to complete the bitmap conversion:
    • 50% Threshold converts pixels above medium gray to white and below medium gray to black, resulting in a high-contrast image ( Figure 3.10 ).

      Figure 3.10 50% Threshold results in a high-contrast image.Bitmap modecolorsmodeschangingDiffusion Dither option50% Threshold optionPattern Dither option

    • Pattern Dither converts areas of gray into geometric patterns ( Figure 3.11 ).

      Figure 3.11 Pattern Dither creates geometric patterns based on areas of gray.

    • Diffusion Dither results in a grainy, graphic look ( Figure 3.12 ).

      Figure 3.12 Diffusion Dither results in a grainy, posterized look.

  5. Click OK to convert the image to Bitmap mode.

To convert an image to indexed color:

  1. From the Image menu, select Mode > Indexed Color ( Figure 3.13 ).

    Figure 3.13 Choose Image > Mode > Indexed Color to convert an RGB image to indexed color.

    The Indexed Color dialog box appears.
  2. Choose Palette, Dither, and other options displayed in the dialog box ( Figure 3.14 ).

    Figure 3.14 The Indexed Color dialog box includes options for choosing colors, palettes, and dithering. This figure shows the dialog box on a Macintosh.

    Palette options allow you to choose the best color palette, taking into account where the image will ultimately be viewed. See the sidebar "Indexed Color Palette Options" for a summary of the different Palette options. The Forced option lets you lock in specific colors so that they are not changed in the conversion process. You can choose to lock in Black and White, which is particularly useful if you have a large area of white or black in the background, as well as Primaries (white, red, green, blue, cyan, magenta, yellow, and black). Choosing the Forced Web option protects all 216 "Web-safe" colors in the palette from being altered.
  3. Click OK to confirm your choices.

Managing color

You've learned some color basics, but before going any further, you may want to take a couple of steps to ensure that the color you see on your monitor will be reasonably accurate when you decide to print or send images to the Web. Fortunately, color management in Photoshop Elements is very simple and doesn't require any labor-intensive chores on your part.

You should first make sure that the colors you see on the monitor are reasonably accurate, and represent what others will see on their monitors. Calibrating your monitor is a particularly good idea if you have an older monitor or have inherited it from a friend or relative (you don't know what they might have done to the monitor settings). If you have a newer monitor, it probably came with an accurate calibration from the factory. In that case, as you go through the following steps, you may find that no changes are needed.

If you prefer, you can also choose color settings optimized for either Web graphics or color printing.

To calibrate your monitor with Adobe Gamma:

  1. Start Adobe Gamma, which you'll find in the Control Panel options window ( Figure 3.15 ).

    Figure 3.15 The Adobe Gamma control panel is located with the other control panel options.

    The Adobe Gamma start screen appears. If you've calibrated your monitor before, you may be launched to the Gamma control panel directly. If so, go to step 3.
  2. From the Adobe Gamma start screen ( Figure 3.16 ), do one of the following:
    • Click Step by Step (Wizard) to adjust your color settings using the onscreen instructions.
    • Choose Control Panel, click Next, and follow steps 3, 4, and 5.

    Figure 3.16 The Adobe Gamma utility is used to calibrate your monitor for Windows XP. It includes a Step by Step mode that guides you through the monitor calibration process.Adobe Gammadialog boxAdobe Gammamonitor color calibrationcolorsmanagementmonitor calibrationdialog boxesAdobe Gammamonitorscolor calibration

  3. When you come to the gamma settings screen, uncheck the View Single Gamma Only check box ( Figure 3.17 ).

    Figure 3.17 Setting up Adobe Gamma ensures that the color images on your screen are represented accurately. In this dialog box, unchecking View Single Gamma Only lets you adjust the red, green, and blue values on your monitor.

    Three color boxes appear, representing the red, green, and blue colors displayed by your monitor ( Figure 3.18 ).

    Figure 3.18 To make adjustments to the red, green, and blue values, move the color slider back and forth until the inside and outside boxes match as closely as possible. Usually, the colors will match closest around the midpoint of the sliders' range.Adobe Gammamonitor color calibrationcolorsmanagementmonitor calibrationmonitorscolor calibration

  4. Using the sliders, match the inner colors to the outer colors in the boxes.
  5. Click OK, then in the Save As dialog box, click Save to save your changes. The monitor profile is saved in the profiles folder.

To choose color settings:

  1. From the Edit menu, choose Color Settings ( Figure 3.19 ).

    Figure 3.19 Choose Edit > Color Settings to bring up the Color Settings dialog box.

    The Color Settings dialog box appears with three color management options plus the option to choose No Color Management ( Figure 3.20 ).
    • Always Optimize Colors for Computer Screens displays images based on the sRGB color profile and is the default setting. It's a good all around solution, particularly if you are creating images to be viewed primarily onscreen.
    • Always Optimize for Printing displays color based on the AdobeRGB profile. Although the image you see onscreen may display with only subtle color differences (as compared to sRGB), you will generally get truer, more accurate color when you send the image to print.
    • Allow Me to Choose will default to sRGB, but if the image contains no color profile, you'll have the option of choosing AdobeRGB.

    Figure 3.20 Choose a color management option best suited to the final output of your image.

  • + Share This
  • 🔖 Save To Your Account