Scanning Basics

Using the Tone Curve

Saving your own tone curve
Deleting a customized tone curve
Closing the Tone Correction dialog box

The tone curve provides you with a versatile means for adjusting the intensity of the colors of the image being scanned. You can adjust the shadow, mid-tone, and highlight values, which helps to ensure well-balanced coloring of the image.

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 appears dimmed and is not available when Pixel Depth is set to Black & White and Halftone is set to None, or B/W Option is set to Text Enhancement Technology in the Image Type dialog box.

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

Tone Curve Name list

Use this list box to select a preset tone curve. There are six preset tone curves available as shown below, and you can add your own curves to the list using the procedure in the next section, Saving your own tone curve.

Curve Name	Highlight	1/4 Tone	Midtone	3/4 Tone	Shadow	Description
Linear	245	192	128	64	8	Default curve
Lighten	245	193	133	74	4	Lightens dark image
Darken	245	152	82	38	11	Darkens bright image
Flat Contrast	245	182	129	72	2	Reduces contrast
High Contrast	245	204	129	51	2	Increases contrast
Open Shadow	245	193	129	80	5	Lightens dark shadows

When you select a curve from the Tone Curve Name list, the settings in the Tone Correction dialog box change accordingly.

Channels

Click an option button under channels to select the color whose tone curve you want to adjust. When the master channel at the top is selected, your adjustments affect all three colors. Selecting one of the other channels allows you to adjust red, green, or blue only.

Tone curve editor

Moving the mouse pointer into the tone curve editor causes it to change to a finger. Use this pointer to drag any of the five points in the curve and change its shape. The x-axis of the curve is the brightness of the original (input values) while the y-axis is the brightness of the scanned image (output values).

To change the tone curve back to its default, select Linear from the Tone Curve Name list.

Output values

These are the current values for output data in accordance with the current locations of the points inside the tone curve editor. These values change when you drag points in the tone curve editor, or you can enter values here to change the shape of the tone curve. Each value can be adjusted within the range of 0 to 255.

Note:

Each output value name has a check box to the left of it. Highlight and Shadow are always selected, but you can select or clear 1/4 Tone, Midtone, and 3/4 Tone by clicking their check boxes.

When a value's check box is clear, its point on the tone curve editor automatically shifts to smooth out the tone curve when one of the other points is moved.

When a value's check box is selected, it means that its point is fixed and it will not shift when other points are moved.

Saving your own tone curve

Use the following procedure to assign a name to a tone curve you have customized and want to save for later use:

Modify the tone curve settings as desired. This causes the name shown in the Tone Curve Name list to change to User Defined.

After customizing the tone curve, enter a name for the new curve (up to 32 characters) in the list box.

Click Save to save your new tone curve settings under the name you specified.

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Deleting a customized tone curve

Use the following procedure to delete a custom tone curve. You cannot, however, delete the six preset tone patterns.

Use the Tone Curve Name list to select the custom tone curve you want to delete.

Click Delete.

When a dialog box appears, click Yes to delete the curve.

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Closing the Tone Correction dialog box

You can close the Tone Correction dialog box by clicking either OK or Cancel.

Clicking OK applies the current Tone Correction dialog box settings and closes the dialog box. Clicking the close button in the upper right corner of the dialog box has the same affect as clicking OK.

Clicking Cancel closes the dialog box without applying the current dialog box settings.

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