Histogram Tool - Epson 600 User Manual

Advanced Scanning
For example, if you're scanning a photograph of a child
standing in shadow, decreasing the gamma value
would increase the contrast between the child's skin
tone and the shaded area, thus making it easier to see
the subject.

Histogram Tool

A histogram is a graph that represents values as
horizontal or vertical lines.
The histogram tool uses vertical lines to show the
intensity of the various tones in an image. The height
of a line indicates the intensity of the tone.
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