CODEWITHSUNDEEP
pythonimage-processingmatplotlib
Mustafa
Mustafa

Reputation: 129

How to plot the equalized histogram of an image with Python?

So this is my code. The variable img is the original image. The variable eq is the equalized image.

from matplotlib.pyplot import imread, imshow, show, subplot, title, get_cmap, hist
from skimage.exposure import equalize_hist


img = imread('images/city.tif')
eq = equalize_hist(img)

subplot(221); imshow(img, cmap=get_cmap('gray')); title('Original')
subplot(222); hist(img.flatten(), 256, range=(0,256)); title('Histogram of      origianl')
subplot(223); imshow(eq, cmap=get_cmap('gray'));  title('Histogram Equalized')
subplot(224); hist(eq.flatten(), 256, range=(0,256));

show()

Now when I run, the code, I get the histogram of the original just fine. But the histogram of the equalized is incorrect. This is all of my output

enter image description here

What am I doing wrong ?!?!

EDIT: The builtin matlab commands from the answer works fine for the particular image

enter image description here

Upvotes: 0

Views: 5023

Answers (1)

Mr Fooz
Mr Fooz

Reputation: 111856

It looks like it's converting the image from uint8 format (integer values between 0 and 255 inclusive) to a float32 or float64 format (floating point values between 0 and 1 inclusive). Try eq = np.asarray(equalize_hist(img) * 255, dtype='uint8').

Upvotes: 4

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