Canon MultiPASS C50 Software User's Manual page 105

To adjust the contrast or brightness of an image:
1. On the Tone tab, click the Contrast/Brightness button.
2. To adjust the contrast or brightness for a particular colour, select the
colour in the Channel list box. Otherwise, leave the channel set to
Master.
3. Move the Contrast and Brightness sliders to the left for less contrast or
brightness, and to the right for more contrast or brightness, until the
desired contrast is achieved.
The image in the preview area reflects your changes.
6-22 Scanning Chapter 6