The stationarity of the training image is preferably characterized by {HEAD ~ statistical measures} of orientation stationarity, {TAIL ~ scale stationarity}, and category distribution stationarity 
of
The stationarity of the training image is preferably characterized by { HEAD ~ statistical measures } of orientation stationarity , { TAIL ~ scale stationarity } , and category distribution stationarity
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH