scikit-image can not import an image

Question

Environment:

Python 3.7.0
After creating a virtualenv, scikit-image is via pip installed.
scikit-image==0.16.2, Pillow==7.1.1
Anaconda on Linux

Source Code:

from skimage.io import imread
file_path = "image_you_like.png"
img = imread(file_path, plugin="pil", as_gray=False)

Expected Result:

img is a numpy array of an image.

Actual Result:

Do not trust the line number, because I inserted a few print functions.

~/Python/experiment/venv/lib/python3.7/site-packages/PIL/PngImagePlugin.py in _seek(self, frame, rewind)
    789 
    790             try:
--> 791                 cid, pos, length = self.png.read()
    792             except (struct.error, SyntaxError):
    793                 break

AttributeError: 'NoneType' object has no attribute 'read'

Question

How can I prevent this error and read an image?

After some analysis I found that imread works if plugin="matplotlib" or plugin="imageio". The problem is that some functions such as skimage.data.camera call imread with plugin="pil" and therefore I can not try any sample image of scikit-image.

[EDIT]

from skimage.io.manage_plugins import plugin_store
print(plugin_store["imread"])

prints the following

[('imageio', <function imread at 0x7efe39112c20>), ('matplotlib', <function imread at 0x7efe37f51290>)]

So "pil" can not be found in the list.

You must have checked this but "Does the image exists in the `cwd`?" I ask because I tried the code above and it worked. — DarK_FirefoX, Apr 02 '20 at 23:26
It definitely exists. Therefore the code will work (on my env) if I change only the plugin option. — H. Shindoh, Apr 02 '20 at 23:30
What I meant was I tried with `plugin=pil` and it worked. Could you explain yourself better? — DarK_FirefoX, Apr 02 '20 at 23:36
I understand what you meant. I meant that the image does exist. — H. Shindoh, Apr 02 '20 at 23:40
Can you try `io.find_available_plugins()` and check if `pil` is in there? — DarK_FirefoX, Apr 02 '20 at 23:51
I found `'pil': ['imread', 'imsave', 'imread_collection']` in the result. — H. Shindoh, Apr 02 '20 at 23:54
You could try `io.use_plugin('pil', 'imread')` to load the plugin... And then try loading the image..Let me know if it works to write an answer, cause this is a very interesting thing. Also, why wouldn't it be available from the start? — DarK_FirefoX, Apr 02 '20 at 23:56

score 2 · Accepted Answer · answered Apr 03 '20 at 21:30

2

This issue was reported on github.

As a user the easiest solution is to downgrade the version to 6.2.2.

answered Apr 03 '20 at 21:30

H. Shindoh

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