Color Correct Your Images in Photoshop Elements 4

This chapter is from the book

Photoshop Elements 4 for Windows: Visual QuickStart Guide

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This chapter is from the book

This chapter is from the book 

Photoshop Elements 4 for Windows: Visual QuickStart Guide

Learn More Buy

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.

The HSB Color Model

The RGB model isn't the only way to translate and interpret color. For some purposes, it's useful to describe color in terms of the HSB model. H represents the color's overall hue (or how you'd characterize it in the color spectrum—for example, is that flower blossom "purple" or "teal"). S stands for saturation, the purity of the color, and B stands for brightness, or how light or dark the color is. Although you can't convert an image to HSB mode, you can make color selections and changes using either RGB or HSB from within the Color Picker ( Figure 3.4 ) and with many of the color-adjustment tools covered later in this chapter. Say, for example, you want to color something bluish-green. How do you describe that in terms of red, green, and blue? If you're working in the HSB model, it's relatively easy. In the toolbox, click the foreground or background color selection box to access the Color Picker. Using the Color Picker, just click the H button, find the basic color on the Hue slider, and then choose the specific shade from the large square on the left, which shows all the variations of saturation and brightness within that hue.

Figure 3.4 The Color Picker includes access to the hue, saturation, and brightness (HSB) of your image.

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.

   The History of Web-Safe Color

   If you're familiar with the creation of graphics or images specifically for the Web, you may already know about Web-safe or browser-safe colors. For those of you new to this buzzword, Web-safe colors are the 216 colors that can be accurately displayed on all color computer monitors regardless of age or platform. Here's the background.

   Back in the pioneer days of the Web—in the mid-1990s—a lot of computer systems still used 256-color cards (also known as 8-bit color). This meant that the monitors on these systems could display only 256 colors at any given time. You (or your kids) may even still have a few CD-ROM games designed around this limitation; you'll know them because they ask you to change the display to 256 colors—in other words, to use the Web-safe palette.

   But even though the palette consists of 256 colors, only 216 of those colors are considered Web safe. That's because Windows and Macintosh computers share only 216 colors, each reserving the remaining colors for system use. Thus, you're left with 216 colors that are guaranteed to appear with absolute accuracy regardless of platform. Surprisingly, even using just these 216 colors, your images can come out looking pretty good.

   Today, even the most basic PCs come out of the box with the capability of displaying thousands—or, more often, millions—of colors, and there are very few 8-bit systems still in use. However, because Windows and Macintosh computers still display some colors a little bit differently, using the Web-safe palette is the only way to ensure that your colors look exactly the same on both systems.

   Bottom line? If you're not concerned about folks running older computer systems, or with the slight color differences in PC and Macintosh systems, use all of the colors your system came with. But if you want to make sure that absolutely all viewers can see your images in the exact colors you intended, stick to the Web-safe color palette.

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.