App with camera and a little lag
I’ve set up an Xcode project for an iPad app, coded in Swift, that takes video input from the front camera and displays the individual frames on screen.
As can be seen in the video above, there is a little lag that I do not (yet) know the source of. There are a few potential experiments one could do here:
- Find out if this is display lag, image processing lag (only conversions between sensor data and displayable images at the moment), or a combination?
- How much lag can the statistical correlation handle between eye and on-screen movement before drifting apart and causing problems?
In regards to (1), since the front camera can’t provide more than 30 fps there will be some lag but I think this looks like more than that. I have double checked that the profiler reports the app updating the image view at 30 fps so that part seem to work as it should.
In regards to (2), eye movements should be small and slow compared to me waving my hand in front of the camera. My initial guess is that this lag is not significant enough to pursue, at least not at this point.