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