moments_region_2nd_rel

moments_region_2nd_rel_invar ( Regions : : : PHI1, PHI2 )

Geometric moments of regions.

The operator moments_region_2nd_rel_invar calculates the scaled relative moments (PHI1, PHI2).

Calculation: The moments PHI1 and PHI2 are defined by:

                    PHI1 = V20 + V02,
		      PHI2 = (V20 + V02)^2 + (V11)^2 .

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).

Parameters

`Regions` (input_object)	region(-array) `->` object
Regions to be examined.

`PHI1` (output_control)	real(-array) `->` real
Moment of 2nd order.

`PHI2` (output_control)	real(-array) `->` real
Moment of 2nd order.

Result

The operator moments_region_2nd_rel_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 handling is raised.

Parallelization Information

moments_region_2nd_rel_invar is reentrant and automatically parallelized (on tuple level).

Possible Predecessors

threshold, regiongrowing, connection

Alternatives

moments_region_2nd

See also

elliptic_axis

Module

Region processing