Determines which region feature value to compute.

Values of this enumeration:

• Area - Total area of region. This feature can be computed by RegionArea.
• BoundingBoxBottom - Bottom position of region bounding box. Bounding box of a region can by obtained by RegionBoundingBox.
• BoundingBoxHeight - Height of region bounding box. Bounding box of a region can by obtained by RegionBoundingBox.
• BoundingBoxLeft - Left position of region bounding box. Bounding box of a region can by obtained by RegionBoundingBox.
• BoundingBoxRight - Right position of region bounding box. Bounding box of a region can by obtained by RegionBoundingBox.
• BoundingBoxTop - Top position of region bounding box. Bounding box of a region can by obtained by RegionBoundingBox.
• BoundingBoxWidth - Width of region bounding box. Bounding box of a region can by obtained by RegionBoundingBox.
• Circularity_BoundingCirclePreserving - Ratio of region area to area of its minimal bounding circle. This feature can by calculated by RegionCircularity.
• Circularity_PerimeterPreserving - Ratio of region area to area of circular region with the same perimeter as in source region. This feature can by calculated by RegionCircularity.
• Circularity_RadiusPreserving - Ratio of region area to area of circular region with the same radius as in source region. This feature can by calculated by RegionCircularity.
• Convexity - Ratio of region area to area of its convex hull. For details, see RegionConvexity.
• DiameterLength - Length of region diameter. Read more: RegionDiameter.
• Elongation - Ratio of region length to its width. For details, see RegionElongation.
• MassCenterX - OX coordinate of region mass center. Mass center of a region can be calculated by RegionMassCenter.
• MassCenterY - OY coordinate of region mass center. Mass center of a region can be calculated by RegionMassCenter.
• MajorAxisLength - Length of the region major elliptic axis. Region axes can be determined by RegionEllipticAxes.
• MinorAxisLength - Length of the region minor elliptic axis. Region axes can be determined by RegionEllipticAxes.
• NumberOfHoles_EightDirections - Number of region holes computed using EightDirections connectivity by RegionNumberOfHoles.
• NumberOfHoles_FourDirections - Number of region holes computed using FourDirections connectivity by RegionNumberOfHoles.
• PerimeterLength - Length or region perimeter. Read more: RegionPerimeterLength.
• Rectangularity - Ratio of region area to its bounding rectangle area. For details, see RegionRectangularity.
• Thickness - Diameter of the biggest inscribed circle.
• Complexity - Complexity of the perimeter.
• Dispersion - Scale-invariant standard deviation of the distance of the region's points to the center.