The histogram is a graphical representation that maps the brightness of pixels in a digital image from pure black to pure white, showing how many pixels are at each brightness level. It allows viewers to judge the tonal distribution of an image at a glance, with the left side representing dark tones, right for bright, and middle for midtones. The histogram plots the number of pixels for each brightness value from 0 for pure black to 255 for pure white.

1. Digital Imaging &
the Histogram
Photo Fundamentals

2. *Histogram is a map of pixels on a scale
from pure black to pure white.
*Shows the brightness/darkness of each
pixel represented on this scale and how
many of these pixels are in each zone.
*Left represents the black/Dark end. Right
represents the white/Bright end and the
middle is perfect middle Gray.

3. It acts as a graphical representation of the
tonal distribution in a digital image.
It plots the number of pixels
for each tonal value.
By looking at the histogram for a specific
image a viewer will be able to judge the
entire tonal distribution at a glance.

4. 0 is Pure Black 255 is Pure
White

9. Underexposed

10. Perfect
Exposure

11. Over Exposed

12. Extra Over
Exposed