HISTOGRAM OF AN IMAGE

This program perform intensity transform of an image using histogram processing.

Intensity transformation functions extracted from image intensity histograms play a
basic role in image processing in areas such as enhancement, compression, segmentation, and
description.
The histogram of a digital image with L total possible intensity levels in the range [0,G]
is defined as the discrete function,
h(rk)= nk
rk is the kth intensity level in the interval [0,G].
Value of G is 255 for class uint8.
Often it is useful to work with normalized histograms as
p(rk)= h(rk)/n
= nk/n
Where n is total no. of pixels in the image.
The core function in the toolbox for dealing with image histogram is
h= imhist (f,b),
where f is input image, b is no. of bins. Default value of b is 256.
Normalized histogram is,
p= imhist (f,b)/numel(f)