Opponent Colors Image Subtraction

I did some more experimenting on image subtraction in different color space. I used two frames from the daytime footage. Serge suggested using opponent colors rather than LAB for better debugging. Opponent Color channels has a simpler model.
Below is plain RGB subtraction.


These two show the subtraction using opponent color channels. I ignore The first one is the green/red one and the second one is blue/yellow. The Blue/yellow seems to bring out difference more, but nosier than RGB.