Microtek 35t plus User Guide

A histogram shows how the brightness and
darkness levels are distributed in an image. The
darkest pixels are at the left, and the lightest pixels
are at the right.

An image with good contrast will have a histogram
with vertical lines spread across the scale from left
to right. Here, the histogram is heavily skewed to
the left, where the darkest pixels are, indicating a
dark image.

To change the histogram (and thus the image), use
the three triangles below the histogram.

In the original histogram, the pixels are mostly to
the left where the black triangle is, indicating a
dark image. The range of spread is also broad and

flat, with almost no pixels for the midtones and
highlights where the gray and white triangles
are.

In the corrected image, the triangles have been
moved to new locations. The net effect is to
narrow the distribution range of the pixels and
lighten the image.

Generally, the best thing to do is to move the
black and white triangles to the start and end of
the curve.

For example, if your graph starts at about value
20 and ends at 240, then move the black
triangle to 20 and the white triangle to 240.
Move the gray triangle to somewhere in the
middle between the black and white triangle.

More detail shows up
in shadow areas

More highlights visible

Pixels are

concentrated

here,

indicating a

dark image.

Histogram has a broad and flat spread, with almost all
pixels in the shadow range (near the black triangle).

Triangles moved to
new positions