ARCore: it takes very long to start tracking

Daniel :

I've tried out the ARCore image tracking sample (java) provided by Google: https://github.com/google-ar/arcore-android-sdk/tree/master/samples

On my test devices (Google Pixel 3a, Samsung Galaxy S9+) the image is detected very fast (TrackingState.PAUSED) but it takes several seconds up to a minute to start tracking (TrackingState.TRACKING) the image or it doesn't work at all. I've had a great start with ARKit on iOS and no problems with tracking images (tracking in under a second).

So my questions are:

1. Why is it detected so fast but not tracked?

2. Has anyone else similar issues? Is there a way to fasten this up?

Chronoz :

Setting the actual size of the image in the augmented image database speeds up the process a lot. While using the method addImage for the AugmentedImageDatabase use the one with three arguments:addImage(String name, Bitmap bitmap, float widthInMeters).