Canon CS-S 4.3 - Manual (Page 38)

CONTENTS
GLOSSARY
INDEX
38
38
Chapter 3
Scanning
To adjust the tones using the Histogram tool:
1. Click the Tone tab, then click the Histogram tool button. The Histogram
graph appears.
2. To adjust the tone of a particular color (red, green, or blue), select the
color from the Channel list. Otherwise, leave the Channel set to Master.
3. Do one of the following to change the black point:
• Click the Black-point Eyedropper button, then click the Eyedropper on
the darkest portion of the image in the preview area. Try zooming in on
the darkest part of the image so you can be sure you are selecting the
shade you want. When you click on the image, all tones darker than
the selected sample tone are adjusted to black.
• Click in the Black-point text box and type a value for the black point.
• Drag the Black arrow at the bottom of the histogram to the point you
want.
In the preview image, all tones darker than this tone are adjusted to black.
4. Do one of the following to change the white point:
• Click the White-point Eyedropper tool, then click on the lightest
portion of the image in the preview area. Try zooming in on the lightest
part of the image so you can be sure to select the shade you want.
• Click in the White-point text box and type a value for the white point.
• Drag the white arrow at the bottom of the histogram to the point you
want.
In the preview image, all tones lighter than this tone are adjusted to white.
5. Do one of the following to adjust the Mid-point. The Mid-point value
should always be between the Black-point and White-point values.
• Click the Mid-point Eyedropper tool, then click the portion of the
image that is in the middle of the range. Try zooming in on that part of
the image so you can be sure to select the shade you want.
• Click in the Mid-point text box and type a value for the midpoint.
• Drag the gray arrow at the bottom of the histogram to the point you
want.