Explain why the discrete histogram equalization technique does not generally yield a flat histogram?
All that histogram equalization does is remap histogram
components on the intensity
scale. To obtain a uniform (­at) histogram would require in
general that pixel intensities
be actually redistributed so that there are L groups of n=L
pixels with the same intensity,
where L is the number of allowed discrete intensity levels and n
is the total number of
pixels in the input image. The histogram equalization method has
no provisions for this
type of (arti®cial) redistribution process.