How to install opencv4nodejs module

Question

Hi I'm trying to use opencv in my Node.js project so I decided to use opencv4nodejs. I tried to install this module by npm and i discovered some errors related to absence of cmake on my computer. So I decided to install cmake by brew. But after this process when I'm trying to install this module the following errors occurs:

MacBook-Air-Micha:webcam-myidea michalkukielka$ npm install opencv4nodejs

> opencv-build@0.1.8 install /Users/michalkukielka/Documents/webcam-myidea/node_modules/opencv-build
> node ./install.js

info No package.json in folder. 
info install if you want to use an own OpenCV installation set OPENCV4NODEJS_DISABLE_AUTOBUILD
info readAutoBuildFile file does not exists: /Users/michalkukielka/Documents/webcam-myidea/node_modules/opencv-build/opencv/auto-build.json /Users/michalkukielka/Documents/webcam-myidea/node_modules/opencv-build/opencv/auto-build.json
info install failed to find auto-build.json: /Users/michalkukielka/Documents/webcam-myidea/node_modules/opencv-build/opencv/auto-build.json
info install 
info install running install script...
info install 
info install opencv version: 3.4.6
info install with opencv contrib: yes
info install custom build flags: 
info install 
info install executing: git --version
info install git --version: git version 2.20.1
info install 
info install executing: cmake --version
info install cmake --version: cmake version 3.15.3
info install 
info install CMake suite maintained and supported by Kitware (kitware.com/cmake).
info install 
info install installing opencv version 3.4.6 into directory: /Users/michalkukielka/Documents/webcam-myidea/node_modules/opencv-build/opencv
Cloning into 'opencv_contrib'...
remote: Enumerating objects: 2160, done.
remote: Counting objects: 100% (2160/2160), done.
remote: Compressing objects: 100% (1916/1916), done.
remote: Total 2160 (delta 365), reused 1101 (delta 134), pack-reused 0
Receiving objects: 100% (2160/2160), 50.82 MiB | 1.57 MiB/s, done.
Resolving deltas: 100% (365/365), done.
Note: checking out 'f26c98365da6af93cb5e49397b571190fca7bb55'.

You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by performing another checkout.

If you want to create a new branch to retain commits you create, you may
do so (now or later) by using -b with the checkout command again. Example:

  git checkout -b <new-branch-name>

Checking out files: 100% (1780/1780), done.
Cloning into 'opencv'...
remote: Enumerating objects: 7328, done.
remote: Counting objects: 100% (7328/7328), done.
remote: Compressing objects: 100% (6260/6260), done.
remote: Total 7328 (delta 1166), reused 3907 (delta 692), pack-reused 0
Receiving objects: 100% (7328/7328), 81.33 MiB | 1.62 MiB/s, done.
Resolving deltas: 100% (1166/1166), done.
Note: checking out '33b765d7979fd8a6038026aa44f6ff1a9c082b7b'.

You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by performing another checkout.

If you want to create a new branch to retain commits you create, you may
do so (now or later) by using -b with the checkout command again. Example:

  git checkout -b <new-branch-name>

Checking out files: 100% (6080/6080), done.
info install running cmake /Users/michalkukielka/Documents/webcam-myidea/node_modules/opencv-build/opencv/opencv,-DCMAKE_INSTALL_PREFIX=/Users/michalkukielka/Documents/webcam-myidea/node_modules/opencv-build/opencv/build,-DCMAKE_BUILD_TYPE=Release,-DBUILD_EXAMPLES=OFF,-DBUILD_DOCS=OFF,-DBUILD_TESTS=OFF,-DBUILD_PERF_TESTS=OFF,-DBUILD_JAVA=OFF,-DCUDA_NVCC_FLAGS=--expt-relaxed-constexpr,-DBUILD_opencv_apps=OFF,-DBUILD_opencv_aruco=OFF,-DBUILD_opencv_bgsegm=OFF,-DBUILD_opencv_bioinspired=OFF,-DBUILD_opencv_ccalib=OFF,-DBUILD_opencv_datasets=OFF,-DBUILD_opencv_dnn_objdetect=OFF,-DBUILD_opencv_dpm=OFF,-DBUILD_opencv_fuzzy=OFF,-DBUILD_opencv_hfs=OFF,-DBUILD_opencv_java_bindings_generator=OFF,-DBUILD_opencv_js=OFF,-DBUILD_opencv_img_hash=OFF,-DBUILD_opencv_line_descriptor=OFF,-DBUILD_opencv_optflow=OFF,-DBUILD_opencv_phase_unwrapping=OFF,-DBUILD_opencv_python3=OFF,-DBUILD_opencv_python_bindings_generator=OFF,-DBUILD_opencv_reg=OFF,-DBUILD_opencv_rgbd=OFF,-DBUILD_opencv_saliency=OFF,-DBUILD_opencv_shape=OFF,-DBUILD_opencv_stereo=OFF,-DBUILD_opencv_stitching=OFF,-DBUILD_opencv_structured_light=OFF,-DBUILD_opencv_superres=OFF,-DBUILD_opencv_surface_matching=OFF,-DBUILD_opencv_ts=OFF,-DBUILD_opencv_xobjdetect=OFF,-DBUILD_opencv_xphoto=OFF,-DWITH_VTK=OFF,-DOPENCV_ENABLE_NONFREE=ON,-DOPENCV_EXTRA_MODULES_PATH=/Users/michalkukielka/Documents/webcam-myidea/node_modules/opencv-build/opencv/opencv_contrib/modules
-- The CXX compiler identification is unknown
-- The C compiler identification is unknown
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - failed
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - failed
CMake Error at CMakeLists.txt:153 (message):
  CMake fails to determine the bitness of the target platform.

    Please check your CMake and compiler installation. If you are cross-compiling then ensure that your CMake toolchain file correctly sets the compiler details.


-- Configuring incomplete, errors occurred!
See also "/Users/michalkukielka/Documents/webcam-myidea/node_modules/opencv-build/opencv/build/CMakeFiles/CMakeOutput.log".
See also "/Users/michalkukielka/Documents/webcam-myidea/node_modules/opencv-build/opencv/build/CMakeFiles/CMakeError.log".
ERR! child process exited with code 1 (for more info, set '--loglevel silly') 

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! opencv-build@0.1.8 install: `node ./install.js`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the opencv-build@0.1.8 install script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/michalkukielka/.npm/_logs/2019-09-07T05_38_02_479Z-debug.log

As I understand there are some new problems with cmake but I cant find solutions for.

Could you help me finish the proces of installation opencv4nodejs?

Answer 1

After trying many other things, this worked for me:

sudo npm install -g opencv4nodejs --unsafe-perm=true --allow-root

Thanks to https://stackoverflow.com/a/64567717/

Answer 2

At the first: Native node modules are built via node-gyp, which already comes with npm by default. However, node-gyp requires you to have python installed. If you are running into node-gyp specific issues have a look at known issues with node-gyp first.

Important note: node-gyp won't handle whitespaces properly, thus make sure, that the path to your project directory does not contain any whitespaces. Installing opencv4nodejs under "C:\Program Files\some_dir" or similar will not work and will fail with: "fatal error C1083: Cannot open include file: 'opencv2/core.hpp'"!**

On Windows you will furthermore need Windows Build Tools to compile OpenCV and opencv4nodejs. If you don't have Visual Studio or Windows Build Tools installed, you can easily install the VS2015 build tools:

npm install --global windows-build-tools

At the second: You should check CMake and compiler installation. If you are cross-compiling then ensure that your CMake toolchain file correctly sets the compiler details.

CMake doesn't (always) listen to CC and CXX. Instead use CMAKE_C_COMPILER and CMAKE_CXX_COMPILER:

cmake -DCMAKE_C_COMPILER=/usr/bin/gcc -DCMAKE_CXX_COMPILER=/usr/bin/g++ ...

See also the documentation.

Alternatively, you can provide a toolchain file, but that might be overkill in this case.

finally: Under OSX we can simply install OpenCV via brew:

brew update
brew install opencv@4
brew link --force opencv@4