Geometric moments of regions.
The operator moments_norm calculates the scaled moments (M20, M02) and the procut of inertia of the axes through the center parallel to the coordinate axes (M11).
Calculation: 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 * SUMME ( (Z0 - Z)^i (S0 - S)^j ), wherein Z and S run throug 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 (input_object) |
region(-array) -> object |
Regions to be examined. |
M11 (output_control) |
real(-array) -> real |
Product of inertia of the axes through the center parallel to the coordinate axes. |
M20 (output_control) |
real(-array) -> real |
Moment of 2nd order (line-dependent). |
M02 (output_control) |
real(-array) -> real |
Moment of 2nd order (column-dependent). |
If F is the area of the region the mean runtime complexity is O(F).
The operator moments_norm returns the value 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