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pythonopencvraspberry-pi

Assertion failure : size.width>0 && size.height>0 in function imshow

I am using OpenCV2 and Python on a Raspberry Pi. When I tried to read a jpeg image and display the image, it shows the following error:

/home/pi/opencv-2.4.9/modules/highgui/src/window.cpp:269: \
  error: (-215) size.width>0 &&  size.height>0 in function imshow.

and the code is:

import cv2
# windows to display image
cv2.namedWindow("Image")
# read image
image = cv2.imread('home/pi/bibek/book/test_set/bbb.jpeg')
# show image
cv2.imshow("Image", image)
# exit at closing of window
cv2.waitKey(0)
cv2.destroyAllWindows()
Solution

  • The image fails to load (probably because you forgot the leading / in the path). imread then returns None. Passing None to imshow causes it to try to create a window of size 0x0, which fails.

    The poor error handling in cv probably owes to its quite thin wrapper layer on the C++ implementation (where returning NULL on error is a common practice).