Building OpenCV on Windows from Source Code using MSYS2 UCRT64 and VS Code (C++)

Table of Contents

• Introduction
• Prerequisites
• Step 1: Update MSYS2
• Step 2: Install Required Packages
• Step 3: Clone OpenCV Source Code
• Step 4: Create Build Directory
• Step 5: Configure the Build with CMake
• Step 6: Build OpenCV
• Step 7: Install OpenCV
• Step 8: Verify with a C++ Example
• Using OpenCV in Visual Studio Code
• Troubleshooting
  • CMake cannot find OpenCV
  • mingw32-make not found
  • Build fails due to memory limits
• Conclusion

Original author	Mahadev Kumar
Compatibility	OpenCV >= 4.x

Note

This tutorial was tested on Windows >= 7 using the MSYS2 UCRT64 environment.

The OpenCV team does not maintain MSYS/Cygwin configuration and does not regularly test it with continuous integration.

---

Introduction

This tutorial explains how to build OpenCV from source on Windows using the MSYS2 UCRT64 toolchain and use it inside Visual Studio Code with C++.

The build configuration uses:

• MSYS2 (UCRT64 shell)
• GCC (UCRT toolchain)
• CMake
• mingw32-make
• VS Code

This method produces native Windows binaries linked against the Universal C Runtime (UCRT).

---

Prerequisites

Install the following software before proceeding:

• MSYS2
• Git
• Visual Studio Code

After installing MSYS2, always open the:

MSYS2 UCRT64 Terminal

Note

Do not use the MSYS, MinGW64, or CLANG64 shells for this build.

---

Step 1: Update MSYS2

Open the MSYS2 UCRT64 terminal and update the system.

pacman -Syu

Restart the terminal if prompted.

---

Step 2: Install Required Packages

Install the required compiler and build tools.

pacman -S mingw-w64-ucrt-x86_64-gcc \
          mingw-w64-ucrt-x86_64-cmake \
          mingw-w64-ucrt-x86_64-make

Verify installation:

gcc --version
cmake --version
mingw32-make --version

Note

Add the following directory to your Windows PATH:

C:\msys64\ucrt64\bin

---

Step 3: Clone OpenCV Source Code

Clone OpenCV and optional contrib modules.

git clone https://github.com/opencv/opencv.git
git clone https://github.com/opencv/opencv_contrib.git

---

Step 4: Create Build Directory

cd opencv
mkdir build
cd build

---

Step 5: Configure the Build with CMake

Run CMake using the MinGW Makefiles generator.

cmake -G "MinGW Makefiles" ../

Note

If you do not want to use opencv_contrib, remove the OPENCV_EXTRA_MODULES_PATH option.

---

Step 6: Build OpenCV

Compile OpenCV.

mingw32-make -j6

Note

If the build fails due to memory limitations, reduce the job count.

Example:

mingw32-make -j4

---

Step 7: Install OpenCV

Install the compiled libraries.

mingw32-make install

After installation, OpenCV will be located in: opencv/build/install

Add the following directory to your Windows PATH:

C:\path\to\opencv\build\install\x64\mingw\bin

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Step 8: Verify with a C++ Example

• Create a folder outside the OpenCV source directory. Example: first-project
• Inside the folder create main.cpp

#include <opencv2/opencv.hpp>
#include <iostream>
 
int main()
{
    std::cout << "OpenCV Version: " << CV_VERSION << std::endl;
 
    cv::Mat img = cv::Mat::zeros(400, 400, CV_8UC3);
 
    cv::imshow("OpenCV Test", img);
    cv::waitKey(0);
 
    return 0;
}

• Create CMakeLists.txt

cmake_minimum_required(VERSION 3.10)
 
project(OpenCVApp)
 
set(OpenCV_DIR "C:/path/to/opencv/build/install/lib/cmake/opencv4")
 
find_package(OpenCV REQUIRED)
 
add_executable(app main.cpp)
 
target_link_libraries(app ${OpenCV_LIBS})

• Build the project.

mkdir build && cd build
cmake -G "MinGW Makefiles" ..
mingw32-make

• Run the program.

./app.exe

Note

If everything is configured correctly, a window should appear displaying a blank image.

---

Using OpenCV in Visual Studio Code

Install the following extensions in VS Code:

• C/C++
• CMake Tools

Open your project folder in VS Code.

Configure the project using CMake.

cmake -G "MinGW Makefiles" ..

Build the project.

mingw32-make

Run the executable.

---

Troubleshooting

CMake cannot find OpenCV

Ensure that OpenCV_DIR is set correctly.

Example:

set(OpenCV_DIR "C:/path/to/opencv/build/install/lib/cmake/opencv4")

---

mingw32-make not found

Make sure the following path is added to the Windows environment variable PATH: C:\msys64\ucrt64\bin

---

Build fails due to memory limits

Reduce parallel build jobs.

mingw32-make -j2

---

Conclusion

You have successfully built OpenCV from source using MSYS2 UCRT64 and verified it with a C++ project in VS Code.

This setup allows you to develop OpenCV-based C++ applications using a fully open-source toolchain on Windows.