1. A system for segmentation, classification, merging, and approximation of lines sought out and tracked by an edge tracking unit tracking an object, the lines being defined according to the edge tracking unit by a sequence of points wherein each point has associated with it a direction angle .alpha., coordiantes x, y, and a direction code RK delivered by the edge tracking unit, comprising: segmentation means for receiving the directional angles .alpha. from the edge tracking unit and for storing in a segment point memory means segments of a line with a determined boundary; mean value calculation means connected to the segment point memory means and to the edge tracking unit for receiving from the segment point memory means said stored segments, for receiving from the edge tracking unit the direction angle .alpha., coordinates x, y, and direction code RK, and for placing in an associated output memory means calculated values; classification means connected to the output memory means and to the segment point memory means for classification of said stored line segments with a determined boundary obtained from the segment point memory means; merging means connected to the segment point memory means and to the output memory means for merging of adjacent, classified segments which are sufficiently alike; and approximation means connected to the segment point memory means and said output memory means for approximation of determined segments.