# Line Segment Constraints

Configure the following limitations:

Parameter | Description
--- | ---
Max Num Lines | The maximum number of lines you want the tool to locate. Be aware the edit control supports this parameter only when your VisionPro installation includes the VisionPro.LineMaxMulti license. See the topic VisionPro Software Security for details on VisionPro security. Set this value to 0 to prevent the tool from returning any line results but still generate a set of outliers for use in your vision application.
Angle Tolerance | The amount of rotation a found line segment can differ from the expected angle that you specify. A low value forces the tool to locate line segments that are more parallel with the gradient search direction.
Coverage Threshold | The minimum acceptable ratio of inliers to the maximum possible number of inliers, or the minimum proportion of edge features along the line segment. For example, specifying a value of 0.5 allows the tool to locate a line segment even though edge points were not detected over 50% of the line. Use Coverage Threshold and Length Threshold simultaneously to meet your line fitting requirements. Be aware that specifying a value of 1.0 forces the tool to locate a line segment only when there are no gaps where no inliers were found.
Length Threshold | Set the minimum acceptable length of a found line segment.