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[Windows] Compiling OpenCV 3.x with opencv_contrib

The following instructions are meant to compile OpenCV specifically for use in mexopencv. OpenCV functionality that is not currently exposed or used by mexopencv are disabled (CUDA acceleration, OpenCL with UMat, etc...). If you intend to compile OpenCV for general use in your own C++ code, we recommend following the instructions in the OpenCV documentation.

Step 1: Download OpenCV

First thing is to obtain OpenCV v3.1.0 (the final version). You have a number of options to choose from:

• download the official installer from SourceForge. This package contains both the source code and prebuilt binaries for Windows (for both x86 and x64 architectures, and select versions of Visual Studio). You should get the file opencv-3.1.0.exe. We need the contents of the sources folder from this package.

  Note: this package doesn't include the extra opencv_contrib modules, so you should obtain it using one of the other options listed below.

• download the source tarballs directly from GitHub. This includes downloading these two:

  • the opencv sources (tag 3.1.0): https://github.com/Itseez/opencv/archive/3.1.0.zip
  • the opencv_contrib sources (tag 3.1.0): https://github.com/Itseez/opencv_contrib/archive/3.1.0.zip

• clone the Git repositories from GitHub. Again there are two parts:

  • the main opencv repository: git clone https://github.com/Itseez/opencv.git
  • the extra opencv_contrib repository: git clone https://github.com/Itseez/opencv_contrib.git

  Once you clone the repositories, you need to switch to the stable 3.1.0 tag in both (git checkout tags/3.1.0).

  Note: You'll need to have access to git either from the command-line using msysgit or Cygwin, or using a graphical user interface like GFW, SourceTree, or SmartGit.

Depending on which option you chose above, extract or move the files to some desired location. For example, set it so that you end up with these files in the following paths:

• C:\OpenCV310\opencv\README.md
• C:\OpenCV310\opencv_contrib\README.md

Step 2: Compile OpenCV

This step requires CMake and a supported C++ compiler (Visual Studio 2015 is used in the instructions below, but you could use any other version, though we recommend VS2010 at the least).

Note: Microsoft recently started offering a full and free version of Visual Studio for personal use: Visual Studio Community 2013 or 2015 (equivalent in functionality to the Professional Edition).

We begin by generating a VS solution to build the sources. Start the cmake-gui.exe tool, and follow these steps:

1. set the source folder as C:/OpenCV310/opencv
2. set the destination folder as: C:/OpenCV310/build
3. press Configure, and choose Visual Studio 14 2015 Win64 as compiler
4. under "BUILD" group, deselect the following:

• BUILD_DOCS, BUILD_PACKAGE, BUILD_PERF_TESTS, BUILD_TESTS
• BUILD_opencv_apps, BUILD_opencv_cuda*, BUILD_opencv_python*, BUILD_opencv_ts

5. under "CPACK" group, deselect all
6. under "OPENCV" group, set

• OPENCV_EXTRA_MODULES_PATH to C:/OpenCV310/opencv_contrib/modules

7. under "WITH" group, deselect:

• WITH_CUDA, WITH_CUFFT, WITH_EIGEN, WITH_OPENCL*, WITH_VTK

8. press Configure again
9. under the newly added "BUILD" group (displayed in red), deselect the following modules:

• aruco
• ccalib
• cvv
• hdf
• matlab
• sfm
• structured_light
• surface_matching
• contrib_world

10. press Configure yet another time
11. press Generate
12. close CMake

Next step is to actually compile OpenCV. Open the created solution file in Visual Studio: C:\OpenCV310\build\OpenCV.sln, and do the following:

1. switch configuration to "Release" mode (or "Debug" if you like)
2. build the solution (this will take a few minutes)
3. select the "INSTALL" project in the solution explorer, and build it
4. close Visual Studio

The resulting folder should be: C:\OpenCV310\build\install (size about 100MB).

Finally you need to add the bin folder (containing the OpenCV DLLs) to the PATH environment variable. Following these instructions, the directory to add is:

• C:\OpenCV310\build\install\x64\vc14\bin

Step 3: Compile mexopencv against OpenCV

Go and download mexopencv project (clone the git repo, or download ZIP file). Say you saved it to have this path:

• C:\OpenCV310\mexopencv\README.markdown

Next start MATLAB, and run the following:

>> cd('C:\OpenCV310\mexopencv')
>> addpath('C:\OpenCV310\mexopencv')
>> addpath('C:\OpenCV310\mexopencv\opencv_contrib')
>> mexopencv.make('opencv_path','C:\OpenCV310\build\install', 'opencv_contrib',true)

(It should take several minutes to finish compilation).

Assuming everything went well, you can finally verify the generated MEX-files by running this in MATLAB:

>> cv.getBuildInformation()

You should see something like:

Congratulation, now you have OpenCV working in MATLAB!