Autotek autocad raster design 2010 用户手册

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Use this tab to increase the detail in one part of the contrast curve without
changing the detail in other parts.

RGB

Specifies the Red, Green, or Blue channel, or the combined RGB channel.
For a grayscale image, you can only select the RGB channel.

Vertical Scale slider

Zooms in on the histogram. As you move the slider upward, the scale is
increased so that low frequency values become more visible and the highest
frequency values become truncated by the top of the window.

Contrast Curve Window

Displays the contrast curve. If you are using a fitted curve or piecewise linear
curve, you can click and drag the curve's points and segments to edit the
curve. You can also right-click to control the appearance of the grid, import
and export curves, or reset the values. You can right-click on a point to
delete the point.

Select Curve Type

Specifies the contrast curve representation in three ways:

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Gamma correction curves result in an exponential curve. It is defined
by either specifying the single exponent (gamma) value or using an
interactive slider.

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Fitted curves are drawn smoothly through points you specify. Points
can be added or removed from the curve, or dragged to modify the shape
of the curve.

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Piecewise Linear curves are constructed of points you add or modify.
Each segment between points is a straight line instead of a curve.

Black

Specify a value in the text box, or move the black clipping slider, to adjust
the point below which color values are displayed as black.

322 | Appendix B   Raster Design Dialog Boxes