I’m writting a C++ library that analyzes images using OpenCV. In order to achieve that, I’m using opencv-swig for generating python bindings of that library. However, when I call the module from python, it isn’t able to find the adequate method for the provided arguments:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/config/.local/lib/python3.10/site-packages/example.py", line 12422, in opencv_receiver
    return _libReconDMI.opencv_receiver(image)
TypeError: in method 'opencv_receiver', argument 1 of type 'cv::Mat'

In C++, opencv_receiver is implemented as shown below:

#include "opencv2/core.hpp"

void opencv_receiver(cv::Mat image){
    (void)image;
}

According to answers like Returning a Opencv Mat type from my Python Code , opencv-swig should be able to generate those bindings. As a consequence, I’m not sure if this problem is a result of using opencv 4.1.2 and swig 4.0.2 as it seems that passing images worked with previous versions of them.

Do you know if opencv-swig requires using a different type in order to receive images?

Is there an alternative way to interface a C++ module that requires receiving OpenCV images which supports newest versions of OpenCV? (For example using numpy.i interface to receive a numpy array containing the image and converting it to a cv::Mat object in C++)

Minimal reproducible example:

In order to reproduce this problem, a minimal project that builds the previously described function was provided here: https://github.com/renatoGarcia/opencv-swig/issues/31#issuecomment-2065932116

Platform details:

• Code server docker image: lscr.io/linuxserver/code-server:latest (https://docs.linuxserver.io/images/docker-code-server/)
• OS: Ubuntu Jammy (according to https://docs.linuxserver.io/FAQ/)
• Compiler: gcc version 11.4.0 (Ubuntu 11.4.0-1ubuntu1~22.04)
• Conan version: 2.2.2
• Python version: 3.10.12
• SWIG version: 4.0.2