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to the histogram only when the color balance of your scanned image does not match
the original picture.
Figure 7. Histogram
However, if the colors in a scanned image appear unclear, the histogram can be
used to make them more to your liking. A histogram shows how bright or dark colors
in the image are, and can be used to adjust these levels.
When using the histogram, it is very helpful to prescan the image. Changes made
to the histogram will instantly be shown on the image in the Prescan Area, allowing
you to immediately judge the effects of the changes!
A histogram is a graphic representation of the tonal distribution (the brightness
and darkness levels) in an image. It plots the number of pixels (dots) at each
brightness level. The histogram displays these levels in the 4 color channels.
The x-axis of the histogram graph represents the color values from darkest (0) at
the far left to the brightest (255) at the far right; the y-axis represents the total number
of pixels at that value. A histogram for a dark image shows most of the pixels at the
left side of the graph. A histogram for a bright image is more heavily weighted to the
right side.
You can manipulate colors in the histogram by changing the values in the
highlight, midtone and shadow slider bars towards the bottom of the window.
The highlight represents the high (bright) end of the color spectrum. If the
highlight value of the Master channel is lowered to 245, all color values
between 245 and 254 will be given the value of 255 (white). Thus, lowering
