Histogram equalization of grayscale images with NumPy

Question

How to do histogram equalization for multiple grayscaled images stored in a NumPy array easily?

I have the 96x96 pixel NumPy data in this 4D format:

Answer 1

As of today janeriksolem's url is broken.

I found however this gist that links the same page and claims to perform histogram equalization without computing the histogram.

The code is:

img_eq = np.sort(img.ravel()).searchsorted(img)