Canon CS-S 4.3 - Manual (Page 36)

CONTENTS
GLOSSARY
INDEX
36
36
Chapter 3
Scanning
Changing Gamma Curve Values
The Gamma curve lets you change the midtones of colors to increase the
contrast between colors, and enhance the overall image. When you increase
the gamma value, light colors are made lighter, and dark colors are made
darker.
For example, if you are scanning a photograph that has many dark tones,
simply adjusting the contrast and brightness settings may not improve the
image as effectively as adjusting the gamma setting.
Use the Gamma slider to change the gamma settings for your image.
To adjust the gamma value of an image:
1. Click the Tone tab, then click the Gamma button.
2. To adjust the gamma value for a particular color (red, green, or blue),
select the color from the Channel list. Otherwise, leave the channel set to
Master.
3. Move the Gamma slider to the left to decrease the midtone intensity, and
to the right to increase the midtone intensity, until the desired effect is
achieved. You can also type a value in the text box. The value must be
between 0.10 and 10.00, inclusive.
For more information about using gamma values to enhance images, see
“Custom Tone Adjustments” in Chapter 5, “Scanning Techniques.”