Could not find module FindOpenCV.cmake ( Error in configuration process)

I wrote a CMakeLists.txt for a project in C++, which uses OpenCV libraries. When I try to create the project using cmake, I get the next configuration problem:

CMake Error at CMakeLists.txt:15 (find_package):
  Could not find module FindOpenCV.cmake or a configuration file for package
  OpenCV.

  Adjust CMAKE_MODULE_PATH to find FindOpenCV.cmake or set OpenCV_DIR to the
  directory containing a CMake configuration file for OpenCV.  The file will
  have one of the following names:

    OpenCVConfig.cmake
    opencv-config.cmake

The fact is that I have an environment variable for the path which I use in Visual Studio with no problems. If I don't include OpenCV, then I can configure and generate with no problem, but I need to solve the problem. I don't understand why cmake cannot find the OpenCV path or how to fix it.

I also used the recommendations mentioned in this link: FindOpenCV.cmake

Does anybody had this problem too?

Solution 1:

The error you're seeing is that CMake cannot find a FindOpenCV.cmake file, because cmake doesn't include one out of the box. Therefore you need to find one and put it where cmake can find it:

You can find a good start here. If you're feeling adventurous you can also write your own.

Then add it somewhere in your project and adjust CMAKE_MODULE_PATH so that cmake can find it.

e.g., if you have

CMakeLists.txt
cmake-modules/FindOpenCV.cmake

Then you should do a

set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_CURRENT_SOURCE_DIR}/cmake-modules)

In your CMakeLists.txt file before you do a find_package(OpenCV)

Solution 2:

If you are on Linux, you just need to fill the OpenCV_DIR variable with the path of opencv (containing the OpenCVConfig.cmake file)

export OpenCV_DIR=<path_of_opencv>