The official documentation writes
OpenCV.js is a JavaScript binding for selected subset of OpenCV functions for the web platform. It allows emerging web applications with multimedia processing to benefit from the wide variety of vision functions available in OpenCV. OpenCV.js leverages Emscripten to compile OpenCV functions into asm.js or WebAssembly targets, and provides a JavaScript APIs for web application to access them. The future versions of the library will take advantage of acceleration APIs that are available on the Web such as SIMD and multi-threaded execution.”
Does this mean that SIMD and multi-threaded execution isn’t yet available, or is the documentation outdated?