Microtek 35t plus Guida Utente

The Curve tool lets you control the gamma, which measures the intensity
affecting the mid-level grays (midtones) of an image. Adjusting the gamma lets
you change the values of the middle range of gray tones without dramatically
altering the shadows and highlights.

In many ways, the Curve tool gives you the most control for adjusting an
image's values, but novice users may take some time to master its intricacies.
The Curve tool applies to grayscale and color images and is not available for
use with line art or halftone scan modes.

To control the mid-
tones, or mid-level
grays, of an image.

When the curve is moved up or down, the
relationship between input value and output value

changes accordingly.

•   In areas where the curve is moved down, pixels

in that portion of the image are 

darkened

.

•   In areas where the curve is moved up, pixels in

that portion of the image are 

lightened

.

Contrast in an image can be seen by the angle of
the line. The 

steeper

 the slope, the higher the

contrast. The closer the line is to horizontal, the
lower the contrast.

The Curve shows the relationship of the
brightness changes across the middle pixels

between the resulting image and the original.

When you open the Curves dialog box, the line
on the graph is diagonal because the Input
and Output values are the same.

The 

x axis

 of the graph represents the original

brightness values of the pixels, from 0 to 255;
the 

y axis 

represents the new brightness

values. Clicking on the diagonal line then plots
a point that can be adjusted.