Can anybody generate opencv.js?

Question

I can\'t generate OpenCV.js using this instructions: https://docs.opencv.org/master/d4/da1/tutorial_js_setup.html

I have this error:

CMake Error:

Answer 1

I'll just list out the parts where installation was slightly different from what was outlined in https://docs.opencv.org/master/d4/da1/tutorial_js_setup.html.

For installing Binaryen, make sure you cd into the emsdk directory and then run these:

./emsdk install binaryen-master-64bit
./emsdk activate binaryen-master-64bit

From the official docs,

python ./platforms/js/build_js.py build_js

doesn't work because you need to add an additional flag --emscripten_dir to specify where the correct path. Note that you want the folder below the emsdk root directory, typically /fastcomp/emscripten/ (for the older “fastcomp” compiler; for the newer upstream LLVM wasm backend it will be /upstream/emscripten/).

I personally used the /upstream/emscripten one

So run this:

python /Users/fangran/opencv/platforms/js/build_js.py build_wasm --build_wasm --emscripten_dir /Users/fangran/emsdk/upstream/emscripten

And it should work and return:

=====
===== Build finished
=====
OpenCV.js location: /Users/fangran/opencv/build_wasm/bin/opencv.js

For more details: refer to this link