IPython freeze on OpenCV destroyAllWindows

If you are running OpenCV on an IPython console, chances are cv2.destroyAllWindows() will freeze your image window and ultimately kill the kernel. To get around this, intersperse your code with the following functions (startWindowThread() and waitKey(1)) :

cv2.namedWindow('image')
cv2.startWindowThread()
.
.
.
cv2.waitKey(1)
cv2.destroyAllWindows()
cv2.waitKey(1)

Should hopefully solve the issue!

OpenCV Error on Anaconda

Error: Unspecified error (The function is not implemented. Rebuild the library with Windows, GTK+ 2.x or Carbon support. If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config

Solution:

conda remove opencv
conda update conda
conda install --channel menpo opencv

This installs the opencv from public channel menpo which works fine.