Error (-215) size.width>0 && size.height>0 occurred when attempting to display an image using OpenCV

Question

I am trying to run a simple program that reads an image from OpenCV. However, I am getting this error:

error: ......\\modules\\highgui\\src\\window.cpp:281:          


        

Answer 1

import numpy as np
import cv2

cap = cv2.VideoCapture(0)
while(True):
    # Capture frame-by-frame
    ret,frame = cap.read()
    cv2.rectangle(frame, (100, 100), (200, 200), [255, 0, 0], 2)
    # Display the resulting frame
    cv2.imshow('frame',frame)
    if cv2.waitKey(25) & 0xFF == ord('q'):
        break

# When everything done, release the capture
cap.release()
cv2.destroyAllWindows() 

**If the camera access for devices is OFF, this code gives an error ;kind of this: cv2.imshow('frame',frame) cv2.error: OpenCV(4.0.0) C:\projects\opencv-python\opencv\modules\highgui\src\window.cpp:350: error: (-215:Assertion failed) size.width>0 && size.height>0 in function 'cv::imshow'

So You should turn ON it**

Answer 2

Try Reinstalling the IDE that you use, with the proper python PATH settings.

Answer 3

    img=cv2.imread('testpaper01-01.png')
    cv2.imshow('image',img)
    cv2.waitKey(0)
    cv2.destroyAllWindows()

You have to mention the same format of your image file in the code(eg:-.jpg/.png/.jpeg/.tif etc.) and the directory of the image file must be same as the source code, I also got the same error but I rectified this way

Answer 4

"error: (-215)" means that an assertion failed. In this case, cv::imshow asserts that the given image is non-empty: https://github.com/opencv/opencv/blob/b0209ad7f742ecc22de2944cd12c2c9fed036f2f/modules/highgui/src/window.cpp#L281

As noted in the Getting Started with Images OpenCV Python tutorial, if the file does not exist, then cv2.imread() will return None; it does not raise an exception.

Thus, the following code also results in the "(-215) size.width>0 && size.height>0" error:

img = cv2.imread('no-such-file.jpg', 0)
cv2.imshow('image', img)

Check to make sure that the file actually exists at the specified path. If it does, it might be that the image is corrupted, or is an empty image.

Answer 5

I think it depends on the IDE + path of the image location issues

1. In python IDLE you can directly run file from same folder where picture is there

example 
img = cv2.imread("kang34.jpg", 0)  # direct use 

2. In IntelliJ IDEA you have to give full path of the image where picture is located

example 
img = cv2.imread("C:\\Users\\DEBASISH\\AppData\\Local\\Programs\\Python\\Python36\\Projects\\kang34.jpg", 0)  # use proper syntax and full path of image location