hamming_distance ( Regions1, Regions2 : : : Distance, Similarity )

Hamming distance between two regions.

The operator hamming_distance returns the hamming distance between two image regions, i.e. the number of pixels of the regions which are different (Distance), i.e. the number of pixels contained in one region but not in the other:

               Distance = |Regions1 intersection ~Regions2| +
                          |Regions2 intersection ~Regions1|
The parameter Similarity describes the similarity between the two regions based on the hamming distance Distance:
             Similarity = ( 1 - Distance ) / ( |Regions1| + |Regions2| )
If both regions are empty Similarity is set to 0. The regions with the same index from both input parameters are always compared.


Attention

In both input parameters the same number of regions must be passed.


Parameters

Regions1 (input_object)
region(-array) -> object
Regions to be examined.

Regions2 (input_object)
region(-array) -> object
Vergleichsregionen

Distance (output_control)
integer(-array) -> integer
Hamming distance of two regions.
Assertion: Distance >= 0

Similarity (output_control)
real(-array) -> real
Similarity of two regions.
Assertion: (0 <= Similarity) && (Similarity <= 1)


Complexity

If F is the area of a region the mean runtime complexity is O(F).


Result

hamming_distance returns the value TRUE if the number of objects in both parameters is the same and is not 0. The behavior in case of empty input (no input objects 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.


Possible Predecessors

threshold__, regiongrowing__, connection


Alternatives

intersection, complement__, area_center


See also

hamming_change_region



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