Opencv – the opencv2 include files

header-filesinstallationopencv

I'm struggling to find the include files that should be in a directory names "opencv2"! I've downloaded OpenCV-2.4.0.tar.bz2 from here and extracted the files and ran cmake, which seemed to build the library successfully.

The problem is that under the "include" directory for "opencv2" there seem to be tons of header files missing. The only header file there at the moment is "opencv.hpp", which includes a whole set of other files which aren't there. Does anyone have any idea where I can get these files from?

Picture of the "opencv2" directory.

Thanks!

Best Answer

The header files of the modules are in their own directories. E.g., you can find calib3d.hpp in /modules/calib3d/include/opencv2/calib3d. The Makefile created by CMake knows these addresses, hence when you make install the header files are all copied into /usr/local/include/opencv2.

Related Solutions

C++ – the difference between #include and #include “filename”

In practice, the difference is in the location where the preprocessor searches for the included file.

For #include <filename> the preprocessor searches in an implementation dependent manner, normally in search directories pre-designated by the compiler/IDE. This method is normally used to include standard library header files.

For #include "filename" the preprocessor searches first in the same directory as the file containing the directive, and then follows the search path used for the #include <filename> form. This method is normally used to include programmer-defined header files.

A more complete description is available in the GCC documentation on search paths.

Python – How to find the location of the Python site-packages directory

There are two types of site-packages directories, global and per user.

Global site-packages ("dist-packages") directories are listed in sys.path when you run:
```
python -m site
```
For a more concise list run getsitepackages from the site module in Python code:
```
python -c 'import site; print(site.getsitepackages())'
```
Note: With virtualenvs getsitepackages is not available, sys.path from above will list the virtualenv's site-packages directory correctly, though. In Python 3, you may use the sysconfig module instead:
```
python3 -c 'import sysconfig; print(sysconfig.get_paths()["purelib"])'
```
The per user site-packages directory (PEP 370) is where Python installs your local packages:
```
python -m site --user-site
```
If this points to a non-existing directory check the exit status of Python and see python -m site --help for explanations.

Hint: Running pip list --user or pip freeze --user gives you a list of all installed per user site-packages.

Practical Tips

<package>.__path__ lets you identify the location(s) of a specific package: (details)

$ python -c "import setuptools as _; print(_.__path__)"
['/usr/lib/python2.7/dist-packages/setuptools']

<module>.__file__ lets you identify the location of a specific module: (difference)
```
$ python3 -c "import os as _; print(_.__file__)"
/usr/lib/python3.6/os.py
```

Run pip show <package> to show Debian-style package information:

$ pip show pytest
Name: pytest
Version: 3.8.2
Summary: pytest: simple powerful testing with Python
Home-page: https://docs.pytest.org/en/latest/
Author: Holger Krekel, Bruno Oliveira, Ronny Pfannschmidt, Floris Bruynooghe, Brianna Laugher, Florian Bruhin and others
Author-email: None
License: MIT license
Location: /home/peter/.local/lib/python3.4/site-packages
Requires: more-itertools, atomicwrites, setuptools, attrs, pathlib2, six, py, pluggy

Best Answer

Related Solutions

C++ – the difference between #include and #include “filename”

Python – How to find the location of the Python site-packages directory

Practical Tips

Related Topic