A method for determining a contour data set of a spectacle frame rim comprising the steps of: a) providing a plurality (N) of three dimensional measured points along a contour of a spectacle frame rim; b) calculating a plurality of best torus that fits P points chosen among the N measured points and where P is equal or more than 4; c) selecting the (T) points among the N measured points that deviate from one of the best torus more than a threshold value; and d) forming the contour data set with (N-T) three dimensional measured points where the T selected points of step c) are excluded from the list of three dimensional measured points of step a).