Common Issues When Using OpenCV with JavaScript

The runtime is not initialized immediately after the script is loaded

WebAssembly is not loaded immediately after the script is loaded, so it will crash.

Assign a function to cv['onRuntimeInitialized'].

CascadeClassifier does not load files

It looks like it's possible in the sample code, but it's not possible with pre-built libraries.

Use the createFileFromUrl function from utils.js.

Memory leaks

You might expect JavaScript to garbage collect (GC) instances once they go out of scope.

Well, it doesn't.

Since objects like cv.Mat or cv.RectVector persist, call the delete method to release them when they are no longer needed.

Otherwise, it will crash.