CODEWITHSUNDEEP
python-2.7opencvwindows-7
Tae-Sung Shin
Tae-Sung Shin

Reputation: 20633

cv2.imread always returns NoneType

cv2.imread is always returning NoneType.

I am using python version 2.7 and OpenCV 2.4.6 on 64 bit Windows 7.

Maybe it's some kind of bug or permissions issue because the exact same installation of python and cv2 packages in another computer works correctly. Here's the code:

im = cv2.imread("D:\testdata\some.tif",CV_LOAD_IMAGE_COLOR)

I downloaded OpenCV from http://www.lfd.uci.edu/~gohlke/pythonlibs/#opencv. Any clue would be appreciated.

Upvotes: 33

Views: 104997

Answers (14)

Yonatan Simson
Yonatan Simson

Reputation: 2575

Sometimes the file is corrupted. If it exists and cv2.imread returns None this may be the case.

Try opening the file כfrom file explorer and see if that works

Upvotes: 0

user2809176
user2809176

Reputation: 1275

In my case helped changing file names to latin alphabet.

Instead of renaiming all files I wrote a simple wrapper to rename a file before the load into a random guid and right after the load rename it back.

import os
import uuid
import cv2

uid = str(uuid.uuid4())


def wrap_file_rename(my_path, function):
    try:
        directory = os.path.dirname(my_path)
        new_full_name = os.path.join(directory, uid)
        os.rename(my_path, new_full_name)
        return function(new_full_name)
    except Exception as error:
        logger.error(error)  # use your logger here
    finally:
        os.rename(new_full_name, my_path)


def my_image_read(my_path, param=None):
    return wrap_file_rename(my_path, lambda p: cv2.imread(p) if param is None else cv2.imread(p, param))

Upvotes: 0

Rutuja Jadhav
Rutuja Jadhav

Reputation: 1

I had a similar issue,changing direction of slashes worked:

Change / to \

Upvotes: 0

Nikita Potemkin
Nikita Potemkin

Reputation: 63

My OS is Windows 10. I noticed imread is very sensitive to path. No any recommendation about slashes worked for me, so how I managed to solve problem: I have placed file to project folder and typed: img = cv2.imread("MyImageName.jpg", 0)

So without any path and folder, just file name. And that worked for me. Also try different files from different sources and of different formats

Upvotes: 2

Jay
Jay

Reputation: 824

In case no one mentioned in this question, another way to workaround is using plt to read image, then convert it to BGR format.

img=plt.imread(img_path)
print(img.shape)
img=img[...,::-1]

it has been mentioned in cv2.imread does not read jpg files

Upvotes: 6

Hu Xixi
Hu Xixi

Reputation: 2117

I also met the same issue before on ubuntu 18.04. 

cv2.imread(path)

I solved it when I changed the path argument from Relative_File_Path to Absolute_File_Path.

Hope it be useful.

Upvotes: 10

Jama Hussein Mohamud
Jama Hussein Mohamud

Reputation: 41

I had a similar problem, changing the name of the image to English alphabetic worked for me. Also, it didn't work with a numeric name (e.g. 1.jpg).

Upvotes: 1

w-m
w-m

Reputation: 11232

First, make sure the path is valid, not containing any single backslashes. Check the other answers, e.g. https://stackoverflow.com/a/26954461/463796.

If the path is fixed but the image is still not loading, it might indeed be an OpenCV bug that is not resolved yet, as of 2013. cv2.imread is not working properly under Win32 for me either.

In the meantime, use LoadImage, which should work fine.

im = cv2.cv.LoadImage("D:/testdata/some.tif", CV_LOAD_IMAGE_COLOR)

Upvotes: 14

Vincent
Vincent

Reputation: 16216

In my case the problem was the spaces in the path. After I moved the images to a path with no spaces it worked.

Upvotes: 10

Qin Heyang
Qin Heyang

Reputation: 1674

I spent some time on this only to find that this error is caused by a broken image file on my case. So please manually check your file to make sure it is valid and can be opened by common image viewers.

Upvotes: 0

Kris Jobs
Kris Jobs

Reputation: 738

just stumbled upon this one.

The solution is very simple but not intuitive.

  • if you use relative paths, you can use either '\' or '/' as in test\pic.jpg or test/pic.jpg respectively
  • if you use absolute paths, you should only use '/' as in /.../test/pic.jpg for unix or C:/.../test/pic.jpg for windows
  • to be on the safe side, just use for root, _, files in os.walk(<path>): in combination with abs_path = os.path.join(root, file). Calling imread afterwards, as in img = ocv.imread(abs_path) is always going to work.

Upvotes: 6

Rich100
Rich100

Reputation: 19

This took a long time to resolve. first make sure that the file is in the directory and check that even though windows explorer says the file is "JPEG" it is actually "JPG". The first print statement is key to making sure that the file actually exists. I am a total beginner, so if the code sucks, so be it. The code, just imports a picture and displays it . If the code finds the file, then True will be printed in the python window. 

import cv2
import sys
import numpy as np
import os

image_path= "C:/python27/test_image.jpg"
print os.path.exists(image_path)



CV_LOAD_IMAGE_COLOR = 1 # set flag to 1 to give colour image
CV_LOAD_IMAGE_COLOR = 0 # set flag to 0 to give a grayscale one
img = cv2.imread(image_path,CV_LOAD_IMAGE_COLOR)
print img.shape
cv2.namedWindow('Display Window') ## create window for display
cv2.imshow('Display Window', img) ## Show image in the window
cv2.waitKey(0) ## Wait for keystroke
cv2.destroyAllWindows() ## Destroy all windows

Upvotes: 2

aivision2020
aivision2020

Reputation: 629

Try changing the direction of the slashes

im = cv2.imread("D:/testdata/some.tif",CV_LOAD_IMAGE_COLOR)

or add r to the begining of the string 

im = cv2.imread(r"D:\testdata\some.tif",CV_LOAD_IMAGE_COLOR)

Upvotes: 8

Benoit Dufresne
Benoit Dufresne

Reputation: 343

I've run into this. Turns out the PIL module provides this functionality. Similarly, numpy.imread and scipy.misc.imread both didn't exist until I installed PIL

In my configuration (win7 python2.7), that was done as follows:

cd /c/python27/scripts
easy_install PIL

Upvotes: -1

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