moments_region_2nd_invar — Geometric moments of regions.
The operator moments_region_2nd_invar calculates the scaled moments (M20, M02) and the procut of inertia of the axes through the center parallel to the coordinate axes (M11).
Z0 and S0 are the coordinates of the center of a region R with the area F. Then the moments Mij are defined by:
Mij = 1/F^2 * SUM ( (Z0 - Z)^i (S0 - S)^j ),
wherein Z and S run through all pixels of the region R.
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).
Regions to be examined.
Product of inertia of the axes through the center parallel to the coordinate axes.
Moment of 2nd order (line-dependent).
Moment of 2nd order (column-dependent).
If F is the area of the region the mean runtime complexity is O(sqrt(F)).
The operator moments_region_2nd_invar 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