OpenCV.js custom build failed in windows machine - opencv

Question

I am trying to build opencv.js by following the steps mentioned in the Open CV [official document][1].
Note: I am trying to make a custom build instead of using the existing [opencv.js][2] library because I want to add some contrib modules as well.
Open CV source version: 4.5.1
Cmake: 3.20.0
Python: 3.7
Emscriptem: [latest][3]
operating system: windows 64 bit
The below is the stack trace of the issue I get when I try to execute the below command in the windows power shell..
emcmake python ./opencv/platforms/js/build_js.py build_js
Stack Trace
emcmake python ./opencv/platforms/js/build_js.py build_js
configure: python ./opencv/platforms/js/build_js.py build_js
Args: Namespace(build_dir='build_js', build_doc=False, build_flags=None, build_loader=False, build_perf=False, build_test=False, build_wasm=False, build_wasm_intrin_test=False, clean_build_dir=False, cmake_option=None, config='D:\\business\\Drapezy\\codetrials\\opencvjs\\opencv\\platforms\\js\\opencv_js.config.py', config_only=False, disable_wasm=False, emscripten_dir='D:\\business\\Drapezy\\codetrials\\opencvjs\\emsdk\\upstream\\emscripten', enable_exception=False, opencv_dir='D:\\business\\Drapezy\\codetrials\\opencvjs\\opencv', simd=False, skip_config=False, threads=False)
Check dir D:\business\Drapezy\codetrials\opencvjs\build_js (create: True, clean: False)
Check dir D:\business\Drapezy\codetrials\opencvjs\opencv (create: False, clean: False)
Check dir D:\business\Drapezy\codetrials\opencvjs\emsdk\upstream\emscripten (create: False, clean: False)
=====
===== Config OpenCV.js build for default target
=====
Executing: ['cmake', '-DPYTHON_DEFAULT_EXECUTABLE=C:\\Users\\girir\\AppData\\Local\\Programs\\Python\\Python37\\python.exe', '-DENABLE_PIC=FALSE', '-DCMAKE_BUILD_TYPE=Release', "-DCMAKE_TOOLCHAIN_FILE='D:\\business\\Drapezy\\codetrials\\opencvjs\\emsdk\\upstream\\emscripten\\cmake\\Modules\\Platform\\Emscripten.cmake'", "-DCPU_BASELINE=''", "-DCPU_DISPATCH=''", '-DCV_TRACE=OFF', '-DBUILD_SHARED_LIBS=OFF', '-DWITH_1394=OFF', '-DWITH_ADE=OFF', '-DWITH_VTK=OFF', '-DWITH_EIGEN=OFF', '-DWITH_FFMPEG=OFF', '-DWITH_GSTREAMER=OFF', '-DWITH_GTK=OFF', '-DWITH_GTK_2_X=OFF', '-DWITH_IPP=OFF', '-DWITH_JASPER=OFF', '-DWITH_JPEG=OFF', '-DWITH_WEBP=OFF', '-DWITH_OPENEXR=OFF', '-DWITH_OPENGL=OFF', '-DWITH_OPENVX=OFF', '-DWITH_OPENNI=OFF', '-DWITH_OPENNI2=OFF', '-DWITH_PNG=OFF', '-DWITH_TBB=OFF', '-DWITH_TIFF=OFF', '-DWITH_V4L=OFF', '-DWITH_OPENCL=OFF', '-DWITH_OPENCL_SVM=OFF', '-DWITH_OPENCLAMDFFT=OFF', '-DWITH_OPENCLAMDBLAS=OFF', '-DWITH_GPHOTO2=OFF', '-DWITH_LAPACK=OFF', '-DWITH_ITT=OFF', '-DWITH_QUIRC=ON', '-DBUILD_ZLIB=ON', '-DBUILD_opencv_apps=OFF', '-DBUILD_opencv_calib3d=ON', '-DBUILD_opencv_dnn=ON', '-DBUILD_opencv_features2d=ON', '-DBUILD_opencv_flann=ON', '-DBUILD_opencv_gapi=OFF', '-DBUILD_opencv_ml=OFF', '-DBUILD_opencv_photo=ON', '-DBUILD_opencv_imgcodecs=OFF', '-DBUILD_opencv_shape_transformer=ON', '-DBUILD_opencv_videoio=OFF', '-DBUILD_opencv_videostab=OFF', '-DBUILD_opencv_highgui=OFF', '-DBUILD_opencv_superres=OFF', '-DBUILD_opencv_stitching=OFF', '-DBUILD_opencv_java=OFF', '-DBUILD_opencv_js=ON', '-DBUILD_opencv_python2=OFF', '-DBUILD_opencv_python3=OFF', '-DBUILD_EXAMPLES=OFF', '-DBUILD_PACKAGE=OFF', '-DBUILD_TESTS=OFF', '-DBUILD_PERF_TESTS=OFF', '-DBUILD_DOCS=OFF', '-DWITH_PTHREADS_PF=OFF', '-DCV_ENABLE_INTRINSICS=OFF', '-DBUILD_WASM_INTRIN_TESTS=OFF', "-DCMAKE_C_FLAGS='-s USE_PTHREADS=0 '", "-DCMAKE_CXX_FLAGS='-s USE_PTHREADS=0 '", 'D:\\business\\Drapezy\\codetrials\\opencvjs\\opencv']
Re-run cmake no build system arguments
-- Detected processor: x86
-- Looking for ccache - not found
CMake Error at cmake/OpenCVCompilerOptimizations.cmake:593 (message):
Compiler doesn't support baseline optimization flags:
Call Stack (most recent call first):
cmake/OpenCVCompilerOptions.cmake:311 (ocv_compiler_optimization_options)
CMakeLists.txt:617 (include)
-- Configuring incomplete, errors occurred!
Traceback (most recent call last):
File "./opencv/platforms/js/build_js.py", line 279, in <module>
File "./opencv/platforms/js/build_js.py", line 192, in config
File "./opencv/platforms/js/build_js.py", line 23, in execute
__main__.Fail: Child returned: 1
[1]: https://docs.opencv.org/master/d4/da1/tutorial_js_setup.html
[2]: https://docs.opencv.org/master/opencv.js
[3]: https://emscripten.org/docs/getting_started/downloads.html
Any ideas to resolve this issue is appreciated.

Answer 1

Building opencv.js on Windows will NOT work, at least according to this open issue. An alternative is to install WSL and use it to build.