| area_center | Area and center of regions. |
| chord_distribution | Distribute the chord lengths of a region. |
| circularity | Shape factor for the roundness of a region. |
| compactness | Shape factor for the compactness of a region. |
| connect_and_holes | Number of connection components and holes |
| contlength | Contour length of a region. |
| convexity | Shape factor for the convexity of a region. |
| direction1 | Pose relation of regions with regard to the coordinate axes. |
| direction2 | Pose relation of regions. |
| elliptic_axis | Parameter of the equivalent ellipse. |
| estimate_foe | Calculate vanishing point from given alignments. |
| estimate_orientation | Estimate the orientation of regions (letters). |
| euler_number | Calculate Euler number. |
| excentricity | Shape features derived from the ellipse parameters. |
| fetch_thickness | Access the thickness of a region along the main axis. |
| get_region_index | Index of all regions containing a given pixel. |
| hamming_distance | Hamming distance between two regions. |
| has_shape | Select regions of a given shape. |
| inner_circle | Largest inner circle of a region. |
| inside_region1 | Choose all regions containing a given pixel. |
| inside_region2 | Test, ob eine Region einen gegebenen Punkt enthält. |
| max_distance | Maximal distance between two boundary points of a region. |
| min_distance1 | Minimum distance between two regions with the help of dilatation. |
| min_distance2 | Minimum distance between the contour pixels of two regions each. |
| moments | Geometric moments of regions. |
| moments_norm | Geometric moments of regions. |
| neighbour | Search direct neighbours. |
| num_chord | Characteristic values for runlength coding of regions. |
| roundness | Shape factors from contour. |
| select_shape | Choose regions with the aid of shape features. |
| select_shape2 | Choose regions having a certain relation to each other. |
| smallest_circle | Smallest surrounding circle of a region. |
| smallest_rectangle1 | Surrounding rectangle parallel to the coordinate axes. |
| smallest_rectangle2 | Smallest surrounding rectangle with any orientation. |