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roundnessroundnessRoundnessroundnessRoundnessRoundness (Operator)


roundnessroundnessRoundnessroundnessRoundnessRoundness — Shape factors from contour.


roundness(Regions : : : Distance, Sigma, Roundness, Sides)

Herror roundness(const Hobject Regions, double* Distance, double* Sigma, double* Roundness, double* Sides)

Herror T_roundness(const Hobject Regions, Htuple* Distance, Htuple* Sigma, Htuple* Roundness, Htuple* Sides)

Herror roundness(Hobject Regions, double* Distance, double* Sigma, double* Roundness, double* Sides)

Herror roundness(Hobject Regions, HTuple* Distance, HTuple* Sigma, HTuple* Roundness, HTuple* Sides)

double HRegion::Roundness(double* Sigma, double* Roundness, double* Sides) const

HTuple HRegionArray::Roundness(HTuple* Sigma, HTuple* Roundness, HTuple* Sides) const

void Roundness(const HObject& Regions, HTuple* Distance, HTuple* Sigma, HTuple* Roundness, HTuple* Sides)

HTuple HRegion::Roundness(HTuple* Sigma, HTuple* Roundness, HTuple* Sides) const

double HRegion::Roundness(double* Sigma, double* Roundness, double* Sides) const

void HOperatorSetX.Roundness(
[in] IHUntypedObjectX* Regions, [out] VARIANT* Distance, [out] VARIANT* Sigma, [out] VARIANT* Roundness, [out] VARIANT* Sides)

VARIANT HRegionX.Roundness(
[out] VARIANT* Sigma, [out] VARIANT* Roundness, [out] VARIANT* Sides)

static void HOperatorSet.Roundness(HObject regions, out HTuple distance, out HTuple sigma, out HTuple roundness, out HTuple sides)

HTuple HRegion.Roundness(out HTuple sigma, out HTuple roundness, out HTuple sides)

double HRegion.Roundness(out double sigma, out double roundness, out double sides)


The operator roundnessroundnessRoundnessroundnessRoundnessRoundness examines the distance between the contour and the center of the area. In particular the mean distance (DistanceDistanceDistanceDistanceDistancedistance), the deviation from the mean distance (SigmaSigmaSigmaSigmaSigmasigma) and two shape features derived therefrom are determined. RoundnessRoundnessRoundnessRoundnessRoundnessroundness is the relation between mean value and standard deviation, and SidesSidesSidesSidesSidessides indicates the number of polygon pieces if a regular polygon is concerned.

The contour for calculating the features is determined depending on the global neighborhood (see set_systemset_systemSetSystemset_systemSetSystemSetSystem).


If p is the center of the area, pi the pixels
and F the area of the contour.
 DistanceDistanceDistanceDistanceDistancedistance  = sum(||p - pi||) / F
 SigmaSigmaSigmaSigmaSigmasigma^2   = sum(||p - pi|| - DistanceDistanceDistanceDistanceDistancedistance)^2 / F
 RoundnessRoundnessRoundnessRoundnessRoundnessroundness = 1 - SigmaSigmaSigmaSigmaSigmasigma / DistanceDistanceDistanceDistanceDistancedistance
 SidesSidesSidesSidesSidessides     = 1.4111 *(DistanceDistanceDistanceDistanceDistancedistance/SigmaSigmaSigmaSigmaSigmasigma)^0.4724

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_systemset_systemSetSystemset_systemSetSystemSetSystem).



RegionsRegionsRegionsRegionsRegionsregions (input_object)  region(-array) objectHRegionHRegionHRegionHRegionXHobject

Region(s) to be examined.

DistanceDistanceDistanceDistanceDistancedistance (output_control)  real(-array) HTupleHTupleHTupleVARIANTHtuple (real) (double) (double) (double) (double) (double)

Mean distance from the center.

Assertion: Distance >= 0.0

SigmaSigmaSigmaSigmaSigmasigma (output_control)  real(-array) HTupleHTupleHTupleVARIANTHtuple (real) (double) (double) (double) (double) (double)

Standard deviation of DistanceDistanceDistanceDistanceDistancedistance.

Assertion: Sigma >= 0.0

RoundnessRoundnessRoundnessRoundnessRoundnessroundness (output_control)  real(-array) HTupleHTupleHTupleVARIANTHtuple (real) (double) (double) (double) (double) (double)

Shape factor for roundness.

Assertion: Roundness <= 1.0

SidesSidesSidesSidesSidessides (output_control)  real(-array) HTupleHTupleHTupleVARIANTHtuple (real) (double) (double) (double) (double) (double)

Number of polygon sides.

Assertion: Sides >= 0


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


The operator roundnessroundnessRoundnessroundnessRoundnessRoundness 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>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>), the behavior in case of empty region is set via set_system('empty_region_result',<Result>)set_system("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>)set_system("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>). If necessary an exception is raised.

Possible Predecessors

thresholdthresholdThresholdthresholdThresholdThreshold, regiongrowingregiongrowingRegiongrowingregiongrowingRegiongrowingRegiongrowing, connectionconnectionConnectionconnectionConnectionConnection



See also



R. Haralick, L. Shapiro “Computer and Robot Vision” Addison-Wesley, 1992, pp. 61



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