How to invert black and white with scikit-image?

Question

I read an image with ndimage, which results in a binary image like this:

enter image description here

I would like to invert the image such that white turns into black, and vice versa.

Help is appreciated.

score 33 · Accepted Answer · edited Dec 23 '19 at 19:35

33

numpy.invert(close_img)

I use invert array. It works for me.

edited Dec 23 '19 at 19:35

BenMorel

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answered Jan 22 '15 at 09:48

Pamungkas Jayuda

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If your image is of dtype bool, then you can simply do ``~close_img``. – Stefan van der Walt Jan 23 '15 at 01:12
If your image is of dtype unsigned integer, you can also use `~close_img`. – Syrtis Major Feb 08 '16 at 15:41

score 18 · Answer 2 · answered Aug 02 '16 at 20:06

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With the devel version of scikit-image (upcomming v0.13), you can use invert(). Example:

from skimage import util 
img = data.camera() 
inverted_img = util.invert(img)

answered Aug 02 '16 at 20:06

François Boulogne

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It worked better than cv2.bitwise_not. Thanks ! – Kubra Altun Feb 28 '21 at 16:00

score 6 · Answer 3 · answered Sep 28 '19 at 02:05

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Here's another method using OpenCV

import cv2

image = cv2.imread('2.png')
invert = cv2.bitwise_not(image) # OR
# invert = 255 - image

answered Sep 28 '19 at 02:05

nathancy

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great, verry usefull – Pamungkas Jayuda Feb 04 '21 at 02:08

score 4 · Answer 4 · answered Mar 20 '16 at 13:55

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If your image is represented with non-negative floating point values topping out at 1.0, you can use 1 - close_image

answered Mar 20 '16 at 13:55

eadsjr

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It can be used for images with a maximum value of 255. Just use `255 - close_image` – Plajerity Aug 04 '20 at 01:44

score 1 · Answer 5 · answered Feb 18 '19 at 17:49

1

I like Pamungkas Jayuda's anwer, but it works only on the assumption that your data is an integer. In my case, I just used simple inversion with a small value on the denominator to avoid division by zero:

1 / (2e5 + img)

answered Feb 18 '19 at 17:49

ambodi

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How to invert black and white with scikit-image?

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