So: I have a couple situations where I have to run a greater pixel difference on my zones in the daytime verses the night. Some people have set up simple cron jobs to switch between day and night settings, etc. but day and night aren't always at the same time, in my application it is affected by shadows that move throughout the course of the year, and even how overcast or bright a particular day is.
So far as i can tell, zoneminder has never tried to implement a percent change threshold for pixel difference, but it seems to me that this might be a simple way to improve performance for some situations?
Just an idea . . .