Goal:
Learning the concept of histogram equailze and how to use it to improve the contrast of pictures
Theory:
If most of the pixel values in an images are concentrated in one pixel range.For example, if a picture is bright as a whole, all pixels should be very high, but the pixel value distribution of a high quality image should be very wide.So we should horizontally stretch the histogram.
In general,this operation will improve the contrast of the image.
First we use Numpy for histogram equlaization, and then learn how to use OpenCV for it.
Numpy