A moving image of a crowd stimulated by an object is input. Based on the moving image, existence of each person constituting the crowd is recognized. A pulse of the person is obtained based on a luminance change of a skin of the person in the moving image. An attribute of the person in the moving image is recognized. The pulse of the person is corrected so as to eliminate a difference in pulse depending on the attribute. A statistical processing value of the pulse of the crowd is obtained by statistically processing the corrected pulse of the person. A numerical index corresponding to the statistical processing value of the pulse of the crowd is outputted as a degree-of-interest.
