When {TAIL ~ the evaluation value} has changed by an amount exceeding a predetermined threshold value, {HEAD ~ the distance information calculation} and three dimensional processing on the plurality of images and object are performed 
When { TAIL ~ the evaluation value } has changed by an amount exceeding a predetermined threshold value , { HEAD ~ the distance information calculation } and three dimensional processing on the plurality of images and object are performed
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH