Adobe 13101332 - Photoshop - Mac, Руководство пользователя

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Using Help | Contents | Index Back 139
Adobe Photoshop Help Making Color and Tonal Adjustments
Using Help | Contents | Index Back 139
Using Levels to adjust color (Photoshop)
In addition to setting the tonal range, you can use Levels to adjust the color balance of an
image.
To use Levels to adjust color balance:
1 Place a color sampler on an area of neutral gray in the image.
2 Open the Levels dialog box. (See “Making color adjustments” on page 132 .)
3 Do one of the following:
•
Double-click the eyedropper tool in the Levels dialog box to display the Color Picker.
Enter the values you want to assign to the neutral gray, and click OK. Then click the
color sampler in the image.
•
Click Options in the Levels dialog box. Click the Midtones color swatch to display the
Color Picker. Enter the values you want to assign to the neutral gray, and click OK.
In general, assign equal color component values to a neutral gray. For example, assign
equal red, green, and blue values to produce a neutral gray in an RGB image.
Using the Curves dialog box (Photoshop)
Like the Levels dialog box, the Curves dialog box lets you adjust the entire tonal range of
an image. But instead of making adjustments using only three variables (highlights,
shadows, midtones), with Curves you can adjust any point along a 0–255 scale while
keeping up to 15 other values constant. You can also use Curves to make precise adjust-
ments to individual color channels in an image.
To adjust tonal range and color balance using Curves:
1 Open the Curves dialog box. (See “Making color adjustments” on page 132 .)
Points along a curve:
A. Highlights B. Midtones C. Shadows
The horizontal axis of the graph represents the original intensity values of the pixels (Input
levels); the vertical axis represents the new color values (Output levels). In the default
diagonal line, all pixels have identical Input and Output values.
Note: For RGB images, Curves displays intensity values from 0 to 255, with shadows (0) on
the left. For CMYK images, Curves displays percentages from 0 to 100, with highlights (0)
on the left. To reverse the display of shadows and highlights at any time, click the double
arrow below the curve.
A
B
C