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resizescikit-image

Skimage resize function returns black images

I'm trying to resize some images that I've loaded using matplotlib's imread function. An example: 

plt.figure()
plt.imshow(imgs[0])
plt.colorbar()
plt.grid(False)
plt.show()

enter image description here

However, when I try to apply the resize function and then replot:

def rescale_image(img):
    """Rescale the jpg range of 0-255 to 0-1"""
    img = resize(img, (100, 100), anti_aliasing=True)
    return img /255
#imgs = [rescale_image(i) for i in imgs]

io = rescale_image(imgs[0])
plt.figure()
plt.imshow(io)
plt.colorbar()
plt.grid(False)
plt.show()

The result is: enter image description here

Why?

UPDATE: The import statements:

%matplotlib inline
import matplotlib.pyplot as plt
from matplotlib.image import imread
from skimage.transform import resize


imgs = [imread(p) for p in paths_list]# paths list is generated by glob.glob on the folder of images
Solution

  • Your image starts out with pixels in the range 0..1. When you resize it, you divide by 255, so the range is now 0..0.003 so it looks black.

    Solution?

    Change this line:

    return img /255

    to this:

    return img