MITSUBISHI ELECTRIC DV1248ST - Manual (Page 41)

In addition, if we take a look at the two images below:
We can see that in Image 1, there is a higher contrast between the brighter and
darker part of the image. Bright and dark pixels occupy a larger portion of the total
image. Therefore, in the histogram there are higher bars in the left (darker side)
and right (brighter side), and in the centre the bars are relatively much lower,
which means that there are only a few midtone pixels in the image.
In image 2, pixels in objects possess greater levels of brightness and darkness.
The distribution is more even than that in Image 1 as well. Therefore, the brighter,
midtone and darker pixels share evenly the total pixels in the image. This will result
in the histogram for Image 2 appearing smoother.
Image 1 Image 2
Brighter images have
brighter pixels, therefore the
bars to the right are higher
than those at the left.
Darker images have darker
pixels, therefore the bars to
the left are higher than
those to the right.