| Operators |
eccentricity — Shape features derived from the ellipse parameters.
eccentricity(Regions : : : Anisometry, Bulkiness, StructureFactor)
The operator eccentricity calculates the three shape features Anisometry, Bulkiness, and StructureFactor for the given Regions:
In the documentation of this chapter (Regions / Features), you can find an image illustrating regions which vary in their anisometry, bulkiness and structur factor.
If more than one region is passed the results are stored in tuples, the index of a value in the tuple corresponding to the index of a region in the input.
In case of empty region all parameters have the value 0.0 if no other behavior was set (see set_system).
It should be noted that, like for all region-moments-based operators, the region's pixels are regarded as mathematical, infinitely small points that are represented by the center of the pixels (see the documentation of elliptic_axis). This can lead to non-empty regions that have Rb = 0. In these cases, the output features that require a division by Rb are set to 0. In particular, regions that contain a single point or regions whose points lie exactly on a straight line (e.g., one pixel high horizontal regions or one pixel wide vertical regions) have an anisometry of 0.
Region(s) to be examined.
Shape feature (in case of a circle = 1.0).
Assertion: Anisometry >= 1.0
Calculated shape feature.
Calculated shape feature.
If F is the area of the region the mean runtime complexity is O(sqrt(F)).
The operator eccentricity returns the value 2 (H_MSG_TRUE) if the input is not empty. The behavior in case of empty input (no input regions available) is set via the operator set_system('no_object_result',<Result>). The behavior in case of empty region (the region is the empty set) is set via set_system('empty_region_result',<Result>). If necessary an exception is raised.
threshold, regiongrowing, connection
elliptic_axis, moments_region_2nd, select_shape, area_center
Foundation
| Operators |