Epson Perfection 640U Reference Manual page 43

Note:
❏ Use of the tone curve is recommended for fine adjustments after you
have previewed the image and adjusted the highlights and the
shadows using Auto Exposure and the Image Controls dialog box.
Use of the tone curve to make initial settings is not recommended.
❏ The Tone Correction button is unavailable whenever Text/Line Art
is selected for the Image Type.
The tone curve is located in the Tone Correction dialog box, which
appears when you click the Tone Correction button in the
Manual mode window. The following section describes how to
use each of the controls in the Tone Correction dialog box.
Tone Correction button
Tone Correction dialog box
Scanning Basics
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