DETECTING APPARATUS FOR DETECTING A CONTOUR OF A MOVING REGION IN A DYNAMIC IMAGE

A detecting apparatus consists of a covariance calculating section for calculating covariances Sij=.intg..intg..intg.(fi*fj)dxdydt (i,j.epsilon.{x,y,t}) with gradients fx, fy and ft of variable densities of pixels, a characteristic value calculating section for calculating characteristic values by utilizing the covariances to express characteristic changes in the variable densities of the pixels, a first-stage pixel classifying section for classifying the pixels into a FIX type denoting that an observed pixel is positioned in a static region of the dynamic image, a MOT type denoting that the observed pixel is positioned inside the moving region and an ACR type denoting that the observed pixel is positioned in a boundary region between the moving and the static regions, a second-stage pixel classifying section for re-classifying the pixels to match a classification type of the observed pixel with those of pixels surrounding the observed pixel, a contour candidate limiting section for limiting a region occupied by pixels re-classified into the ACR type as a candidate region, and a contour drawing section for drawing a contour of the moving section passing through a middle portion of the candidate region.