Abstract:

In order to describe the shape of freehand sketch more accurately,a novel feature description method forfreehand sketch,which is of certain translation invariance,scale invariance and rotation invariance,is proposed bycombining entropy and potential energy.First,in this method,the key contour points in freehand sketch are extrac-ted,and the information entropy of each key point is computed by dividing the region around the point into severalsub- regions.Then,according to the spatial position of key point in the object of freehand sketch,the potentialenergy of key contour point is computed,from which the descriptor vector for the key contour point is obtained incombination with entropy and potential energy.Finally,all the descriptor vectors of key contour points in all trai-ning freehand sketches are clustered to construct a visual code book,on the basis of which a freehand sketch is de-scribed as a feature vector.Experimental results verify the effectiveness of the proposed method.

Key words: freehand sketch, key point description, information entropy, potential energy, clustering