build container:
docker -H luna.local build -t colordetector .
run container:
docker -H luna.local run -e N_SPLITS=10 -it --privileged colordetector
N_SPLITS is the environment veriable indicating the number of horizontal splits of the image
image stream captured by duckiebot
an N_SPLITS*4 matrix, each column represents the number of the pixels in white/yellow/red/other color respectively.