python - What is the cv2.cv replacement in OpenCV3?

Question

I'm using OpenCV3, and with the python bindings there is no cv2.cv module:

In [1]: import cv2

In [2]: from cv2 import cv
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
<ipython-input-2-15a6578c139c> in <module>()
----> 1 from cv2 import cv

ImportError: cannot import name cv

However, I have some legacy code of the form:

hsv_im = cv2.cvtColor(image, cv2.cv.CV_BGR2HSV)

When running this, I get the error:

In [7]: hsv_im = cv2.cvtColor(image, cv2.cv.CV_BGR2HSV)
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-7-e784072551f2> in <module>()
----> 1 hsv_im = cv2.cvtColor(image, cv2.cv.CV_BGR2HSV)

AttributeError: 'module' object has no attribute 'cv'

What is the equivalent of this code in OpenCV3?

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Related questions:

• import cv2 works but import cv2.cv as cv not working

• Is cv2.cv missing in OpenCV 3.0?

Answer 1

From OpenCV 2.X OpenCV 3.0 a few things changed.

Specifically:

• cv2.cv doesn't exists in OpenCV 3.0. Use simply cv2.
• some defines changed, e.g. CV_BGR2HSV is now COLOR_BGR2HSV.

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So you need to change this line:

hsv_im = cv2.cvtColor(image, cv2.cv.CV_BGR2HSV)

to:

hsv_im = cv2.cvtColor(image, cv2.COLOR_BGR2HSV)