Not a direct answer, but there are Cordova plugins using OpenCV on device:
https://github.com/Cloudoki/ImageDetectionCordovaPlugin
This also exists:
https://www.npmjs.com/package/cordova-plugin-scanbot-sdk
https://scanbot.io/en/sdk.html
https://scanbotsdk.github.io/documentation/cordova/
https://github.com/doo/scanbot-sdk-example-cordova