Operators

## Features

List of Operators ↓

This chapter contains operators that allow you to access the different features of regions.

### List of Features

In the following, the available features are illustrated.

'area':

Area of the object

'row':

Row index of the center

'column':

Column index of the center

'row1':

Row index of upper left corner

'column1':

Column index of upper left corner

'row2':

Row index of lower right corner

'column2':

Column index of lower right corner

'width':

Width of the region (parallel to the coordinate axis)

'height':

Height of the region (parallel to the coordinate axis)

'circularity':

Circularity (see circularity)

'compactness':

Compactness (see compactness)

'contlength':

Total length of contour (see operator contlength)

'convexity':

Convexity (see convexity)

'rectangularity':

Rectangularity (see rectangularity)

'ra':

Main radius of the equivalent ellipse (see elliptic_axis)

'rb':

Secondary radius of the equivalent ellipse (see elliptic_axis)

'phi':

Orientation of the equivalent ellipse see elliptic_axis)

'anisometry:'

Anisometry (see eccentricity)

'bulkiness:'

Bulkiness (see operator eccentricity)

'struct_factor:'

Structur Factor (see operator eccentricity)

Radius of smallest surrounding circle (see smallest_circle)

Radius of largest inner circle (see inner_circle)

'inner_width':

Width of the largest axis-parallel rectangle that fits into the region (see inner_rectangle1)

'inner_height':

Height of the largest axis-parallel rectangle that fits into the region (see inner_rectangle1)

'dist_mean':

Mean distance from the region border to the center (see operator roundness)

'dist_deviation:'

Deviation of the distance from the region border to the center (see operator roundness)

'roundness':

Roundness (see operator roundness)

'num_sides':

Number of polygon sides (see operator roundness)

'connect_num':

Number of connection components (see operator connect_and_holes)

'holes_num':

Number of holes (see operator connect_and_holes)

'area_holes':

Area of the holes of the object (see operator area_holes)

'max_diameter':

Maximum diameter of the region (see operator diameter_region)

'orientation':

Orientation of the region (see operator orientation_region)

'euler_number':

Euler number (see operator euler_number)

'rect2_phi':

Orientation of the smallest surrounding rectangle (see operator smallest_rectangle2)

'rect2_len1':

Half the length of the smallest surrounding rectangle (see operator smallest_rectangle2)

'rect2_len2':

Half the width of the smallest surrounding rectangle (see operator smallest_rectangle2)

'moments_m11':

Geometric moments of the region (see operator moments_region_2nd)

'moments_m20':

Geometric moments of the region (see operator moments_region_2nd)

'moments_m02':

Geometric moments of the region (see operator moments_region_2nd)

'moments_ia':

Geometric moments of the region (see operator moments_region_2nd)

'moments_ib':

Geometric moments of the region (see operator moments_region_2nd)

'moments_m11_invar':

Geometric moments of the region (see operator moments_region_2nd_invar)

'moments_m20_invar':

Geometric moments of the region (see operator moments_region_2nd_invar)

'moments_m02_invar':

Geometric moments of the region (see operator moments_region_2nd_invar)

'moments_phi1':

Geometric moments of the region (see operator moments_region_2nd_rel_invar)

'moments_phi2':

Geometric moments of the region (see operator moments_region_2nd_rel_invar)

'moments_m21':

Geometric moments of the region (see operator moments_region_3rd)

'moments_m12':

Geometric moments of the region (see operator moments_region_3rd)

'moments_m03':

Geometric moments of the region (see operator moments_region_3rd)

'moments_m30':

Geometric moments of the region (see operator moments_region_3rd)

'moments_m21_invar':

Geometric moments of the region (see operator moments_region_3rd_invar)

'moments_m12_invar':

Geometric moments of the region (see operator moments_region_3rd_invar)

'moments_m03_invar':

Geometric moments of the region (see operator moments_region_3rd_invar)

'moments_m30_invar':

Geometric moments of the region (see operator moments_region_3rd_invar)

'moments_i1':

Geometric moments of the region (see operator moments_region_central)

'moments_i2':

Geometric moments of the region (see operator moments_region_central)

'moments_i3':

Geometric moments of the region (see operator moments_region_central)

'moments_i4':

Geometric moments of the region (see operator moments_region_central)

'moments_psi1':

Geometric moments of the region (see operator moments_region_central_invar)

'moments_psi2':

Geometric moments of the region (see operator moments_region_central_invar)

'moments_psi3':

Geometric moments of the region (see operator moments_region_central_invar)

'moments_psi4':

Geometric moments of the region (see operator moments_region_central_invar)

#### List of Operators

area_center
Area and center of regions.
area_holes
Compute the area of holes of regions.
circularity
Shape factor for the circularity (similarity to a circle) 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.
diameter_region
Maximal distance between two boundary points of a region.
eccentricity
Shape features derived from the ellipse parameters.
elliptic_axis
Calculate the parameters of the equivalent ellipse.
euler_number
Calculate the Euler number.
find_neighbors
Search direct neighbors.
get_region_index
Index of all regions containing a given pixel.
get_region_thickness
Access the thickness of a region along the main axis.
hamming_distance
Hamming distance between two regions.
hamming_distance_norm
Hamming distance between two regions using normalization.
inner_circle
Largest inner circle of a region.
inner_rectangle1
Largest inner rectangle of a region.
moments_region_2nd
Calculate the geometric moments of regions.
moments_region_2nd_invar
Geometric moments of regions.
moments_region_2nd_rel_invar
Geometric moments of regions.
moments_region_3rd
Geometric moments of regions.
moments_region_3rd_invar
Geometric moments of regions.
moments_region_central
Geometric moments of regions.
moments_region_central_invar
Geometric moments of regions.
orientation_region
Orientation of a region.
rectangularity
Shape factor for the rectangularity of a region.
region_features
Calculate shape features of regions.
roundness
Shape factors from contour.
runlength_distribution
Distribution of runs needed for runlength encoding of a region.
runlength_features
Characteristic values for runlength coding of regions.
select_region_point
Choose all regions containing a given pixel.
select_region_spatial
Pose relation of regions.
select_shape
Choose regions with the aid of shape features.
select_shape_proto
Choose regions having a certain relation to each other.
select_shape_std
Select regions of a given shape.
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.
spatial_relation
Pose relation of regions with regard to the coordinate axes.

 Operators