1. A person clothing feature extraction device comprising: a person region detection part that detects a person's region from input video; a person direction determination part that determines a person's direction in the person's region; a clothing segment separation part that determines a separability of person's clothes in the person's region so as to produce clothing segment separation information reflecting an automatic separability of clothing segments and a separable manner how clothing segments are separated; a clothing feature extraction part, considering the person's direction and the clothing segment separation information, which extracts clothing features representing visual features of person's clothes in the person's region with respect to each clothing segment when clothing segments are automatically separable but which extracts clothing features without separating them when clothing features are not automatically separable; and a clothing feature storage that stores the extracted clothing features.