The information of view outline is one of the important issues in computer Graphics.It plays an important role in automatic partitioning of engineering drawings

assembly diagram processing and dimension arrangement. Lots of experts have proposed many methods to these issues. To improve the efficiency of acquisition of view outline information and solve the problem of existing methods which require angle discriminance and much calculation

this paper puts forward automatically acquires the information of view outline based on midpoint method. At first

this method sorts the candidate path according to the quadrant of coordinate system

and then fleetly eliminates some candidate path by directly comparing their coordinate values. Thirdly

according to the midpoint method

the candidate path which was distinguished arduously can be determined finally. 〖JP2〗The midpoint method only includes shift and subtraction calculation

avoids complex angle calculation and nodical acquisition calculation

so the efficiency of this method can be improved. This method is applicable in automatic organization of complex view outline information. The result of test indicates that this method is a simple

highly efficient and reliable algorithm.