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

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.

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.

I've met the same problem and solved it. Maybe you can firstly do pip uninstall opecv-python and pip uninstall opencv-contrib-python, and then do pip install opencv-python==3.4.4.19 and pip install opencv-contrib-python==3.4.4.19. That's my solution, hope it's helpful.

This is an old thread, but I will add my answer, maybe helpful for someone facing same problem.
cv2.MultiTracker_create() is missing from OpenCV documentation also on 4.5.1.
[https://docs.opencv.org/4.5.1/d8/d77/classcv_1_1MultiTracker.html]
OpenCV contrib modules are known to be "unstable" which means that they can break or change. In my case, I had opencv-python and opencv-contrib-python both 4.5.2, but cv2.legacy.MultiTracker_create() was giving error.
Best solution is to uninstall opecv-python and opencv-contrib-python and reinstall version 4.4.0.46.
This will solve the problem.
pip install opencv-python==4.4.0.46
pip install opencv-contrib-python==4.4.0.46

Related

Boost not found when installing dlib, but its actually installed

Im trying to install dlib for few cv2 projects, but I have problems installing it.I made everything without problem but when I wanted to finally do the python setup.py install It showed me this error message: Could NOT find Boost (missing: python) (found suitable version "1.79.0", minimum required is "1.41.0")
I mean why doesnt it work when it sees my installed Boost 1.79...
Does somebody know how to fix it guys?
Thank you anyways:)
From error log it looks like boost libraries are found, but it's missing specific boost library to integrate with python
You have not mentioned which OS you are using for debian & it's derivatives
sudo apt-get install libboost-python-dev or if you are installing specific version of boost sudo apt-get install libboost-python1.79-dev should install the python module.
If boost is built from sources, during bootstrapping enable python libs to be built
./bootstrap.sh --with-libraries=python,filesystem,serialization
for list of boost libs can be built
./bootstrap.sh --show-libraries

Updating opencv to version 4.5.1

I need to update opencv to version 4.5.1 because there is a function that is not implemented in my current version 3.4.2. (I need to use the SIFT_create function, when I google a bit it seems that they removed it from 3.4.2 because of a patent. However, I have also heard from someone that this function has a different name in 3.4.2, so if you know this different name this is fine as well. I googled it but couldn't find anything about it.)
I tried updating opencv in the anaconda navigator but that didn't work. I tried typing
pip install opencv-python==4.0.0.21
(if I replaced 4.0.0.21 by 4.5.1 it couldn't find the version), but when I type
cv2.__version__
afterwards it still says I'm using version 3.4.2. I found this post: How to upgrade OpenCV in Anaconda (windows)? which says I should use
conda install -c conda-forge opencv=4.3.0
I do this, both the exact same command and the command with 4.3.0 replaced by 4.5.1 but in both cases I only get version 4.0.0 (which apparently also doesn't have the SIFT_create function).
Any idea what I could do?
In the meanwhile I found the answer myself (or rather: with the help of non-internet people).
The problem was that while trying to update opencv, I ended up having two versions of opencv at once. I had opencv 4.5.1 and at the same time I had opencv-python 4.0.0.21 installed. When importing opencv, it chose to import opencv-python in stead of just opencv. When I deleted the opencv-python this fixed the problem.

installing old versions of cv2 using pip

i've been trying to download older versions of cv2 as an easy way to get around not being able to use SIFT.
I've tried the following:
pip install opencv-contrib-python==3.4.2.17
however I get this error:
ERROR: Could not find a version that satisfies the requirement opencv-contrib-python==3.4.2.17 (from versions: 3.4.8.29, 3.4.9.31, 3.4.9.33, 4.1.2.30, 4.2.0.32, 4.2.0.34)
ERROR: No matching distribution found for opencv-contrib-python==3.4.2.17
All the advice I've seen on the site so far tells me to either download these older versions of opencv or to build it myself (which seems like an absolute nightmare)
Anyone have any suggestions on how to install these older versions of cv2?
opencv-contrib-python 3.4.2.17 provides wheels for Pythons up to 3.7. Probably you use Python 3.8.
Use Python 3.7 (or lower). Or compile from sources for 3.8.

sift = cv2.xfeatures2d.SIFT_create() not working even though have contrib installed

So I am trying to use:
sift = cv2.xfeatures2d.SIFT_create()
and it is coming up with this error:
cv2.error: OpenCV(3.4.3) C:\projects\opencv-python\opencv_contrib\modules\xfeatures2d\src\sift.cpp:1207: error: (-213:The function/feature is not implemented)
This algorithm is patented and is excluded in this configuration; Set OPENCV_ENABLE_NONFREE CMake
option and rebuild the library in function 'cv::xfeatures2d::SIFT::create'
I am using Python 3.5.0 and opencv(3.4.3) and I am just using idle. This occured after I tried to install TensorFlow and I have tried looking around and have installed opencv-contrib-python but I am still getting the same error. Thank you in advance and I apologise if I have not included enough info
I had the same problem. It seems that SIRF and SURF are no longer available in opencv > 3.4.2.16. I chose an older opencv-python and opencv-contrib-python versions and solved this problem. Here is the history version about opencv-python, and I use the following code :
pip install opencv-python==3.4.2.16
pip install opencv-contrib-python==3.4.2.16
Edit
For Anaconda User just this instead of pip
conda install -c menpo opencv
this will install cv2 3.4.1 and everything you need to run SIFT
Since SIFT patent expired, SIFT has been moved to the main repo.
To use SIFT in Opencv, You should use cv2.SIFT_create() instead of cv2.xfeatures2d.SIFT_create() now. (xfeatures2d only exists in the contrib package, but sift is part of the main package now.)
Below link will be helpful.
https://github.com/opencv/opencv/issues/16736
Edit: The opencv-contrib-python-nonfree was removed from pypi.
On Linux/ MacOS, I've found a better solution! To access nonfree detectors use:
pip install opencv-contrib-python-nonfree
It may be due to a mismatch of opencv version and opencv-contrib version.
If you installed opencv from the source using CMake, and the source version is different from the version of opencv-contrib-python, uninstall the current opencv-contrib-python and do pip install opencv-contrib-python==<version of the source>.X or an another compatible version.
One version setup that I have running is opencv source (3.2), opencv-python (3.4.0.14) and opencv-contrib-python (3.4.2.17)

When i import parse in ipython , computer say 'parse' it not defined

I think i don't have parse library. So, Where can i get it?
As beginner, I need your help.
I wrote from lxml.html import parse , Computer say name 'parse' is not defined
You actually probably need the lxml package, which was in the comment by cel. It seems to me like your question is concerning how to actually install the package. Everything at PyPi (the Python package index) can be installed in several ways. For me, the easiest is using pip, which is a tool for installing Python packages. Here are some links for how to get pip on your machine for different operating systems: Windows, Mac OSX, or in general.
Once you have pip installed, you go to your command line and type
pip install ['package_name']
where, in your case, package_name would be lxml. Once you do that, your import should work just fine. The full pip documentation is here.
If you prefer to manually install the package, you can download the source and install it according to the Python docs for Python 2.x or 3.x.

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