Attribute Error: MultiTracker_create() Not Found in cv2 on Raspberry Pi

Question

I am currently trying to set up the opencv trackers on a Raspberry Pi. However, when I use the MultiTracker_create() function, it gives me an Attribution Error:

multiTracker = cv2.MultiTracker_create()

AttributeError: module 'cv2.cv2' has no attribute 'MultiTracker_create'

The same code works on my computer, but when I try it on the Pi, it experiences the above error. I am currently using Python 3.5 on the Raspi with OpenCV 3.4.4. My computer uses Python 3.7 with OpenCV 3.4.1.

Thank you in advance for your help.

I have made sure that I am using the correct package: pip3 install opencv_contrib_python

I have also tried to look through the help(cv2) and could not find anything specific about the MultiTracker.

Answer 1

Just stumbled upon this myself. It appears that MultiTracker is no longer part of OpenCV 4.5.1, but you should be able to get it from the legacy package like this:

multiTracker = cv2.legacy.MultiTracker_create()

See https://docs.opencv.org/4.5.1/df/d4a/classcv_1_1legacy_1_1MultiTracker.html

Note that if you subsequently call multiTracker.add(...), you'll need to add the legacy version(s) of the trackers as well.