Difference between plt.imshow and cv2.imshow?

Question

Why is there a difference in the output image when calling the same image using plt.imshow & cv2.imshow()?

Here is my code:

import cv2
import numpy as np
from matplotlib import pyplot as plt

src=cv2.imread('fruits1.jpg') # Source image

plt.subplot(211),plt.imshow(src),plt.title('image')
plt.xticks([]),plt.yticks([])
plt.show()

cv2.imshow('image',src)
cv2.waitKey(0)
cv2.destroyWindow()

Here is the image from plt.imshow:

and the second one is the original image:

Is there some modification required with the plt.imshow()?

OpenCV uses BGR channel ordering, but matplotlib uses RGB. So there is a channel reversal ordering between the two needed when going from one to the other. — fmw42, Dec 30 '22 at 22:16

score 35 · Accepted Answer · answered Aug 11 '16 at 23:24

35

Because OpenCV stores images in BGR order instead of RGB.

Try plt.imshow(cv2.cvtColor(image, cv2.COLOR_BGR2RGB))

See here for an example.

answered Aug 11 '16 at 23:24

laks

366
3
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score 3 · Answer 2 · edited Dec 31 '22 at 01:42

3

OpenCV - BGR and Matplotlib - RGB

OpenCV:

https://docs.opencv.org/2.4/doc/tutorials/introduction/display_image/display_image.html

Matplotlib:

https://matplotlib.org/api/_as_gen/matplotlib.pyplot.imshow.html

edited Dec 31 '22 at 01:42

Cris Luengo

55,762
10
62
120

answered Jun 01 '18 at 09:58

Adam Merckx

1,122
1
14
31

score 1 · Answer 3 · answered Mar 20 '22 at 16:29

1

you can either use :

plt.imshow(cv2.cvtColor(image,cv2.COLOR_BGR2RGB))
                        OR
plt.imshow(image[:,:,::-1])  # here we are reversing the channel order

answered Mar 20 '22 at 16:29

Suman

699
6
5

Difference between plt.imshow and cv2.imshow?

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