Determines which path feature value to compute.

Values of this enumeration:

• BoundingBoxBottom - Bottom position of region bounding box. Bounding box of a path can by obtained by PathBoundingBox.
• BoundingBoxLeft - Left position of region bounding box. Bounding box of a path can by obtained by PathBoundingBox.
• BoundingBoxRight - Right position of region bounding box. Bounding box of a path can by obtained by PathBoundingBox.
• BoundingBoxTop - Top position of region bounding box. Bounding box of a path can by obtained by PathBoundingBox.
• DiameterLength - Length of path diameter, which can be also calculated by PathDiameter.
• Length - Total length of path, computed by PathLength.
• MassCenterX - OX coordinate of path mass center. Mass center of a path is computed by PathMassCenter.
• MassCenterY - OY coordinate of path mass center. Mass center of a path is computed by PathMassCenter.
• PolygonArea - Area of a closed path (polygon). Read more: PolygonArea.
• PolygonCircularity_BoundingCirclePreserving - Circularity computed by PolygonCircularity with BoundingCirclePreserving method.
• PolygonCircularity_PerimeterPreserving - Circularity computed by PolygonCircularity with PerimeterPreserving method.
• PolygonCircularity_RadiusPreserving - Circularity computed by PolygonCircularity with RadiusPreserving method.
• PolygonConvexity - Ratio of polygon area to area of its convex hull. For details, see PolygonConvexity.
• PolygonElongation - Ratio of polygon height to its width, calculated as in PolygonElongation.
• PolygonMajorAxisLength - Length of the path major elliptic axis. Shape axes can determined by PolygonEllipticAxes.
• PolygonMinorAxisLength - Length of the path minor elliptic axis. Shape axes can determined by PolygonEllipticAxes.
• PolygonRectangularity - Ratio of shape area to it bounding rectangle area. See more: PolygonRectangularity.
• Size - Number of characteristic points on path returned by PathSize.