DIPlib Documentation - ©1995-2010 Quantitative Imaging Group, Delft University of Technology.

FeatureShape

Measure shape parameters of the object

SYNOPSIS

#include "dip_measurement.h"

dip_int dip_FeatureShapeID ( void )

FUNCTION

dip_FeatureShapeID returns the ID value of this measurement function, that is registered by Initialise.

This function is a composite measurement function, that uses FeatureSize, FeaturePerimeter, and FeatureFeret to measures the following shape characteristics of 2D objects:

Squarity      = area / ( s * sp )
Circularity   = area / ( Pi/4 * sp^2 )
Triangularity = area / ( 2 * s * sp )
Ellipsity     = area / ( Pi/4 * s * sp )
Elongation    = p / l

with area the size, s the shortest Feret diameter, l the longest Feret diameter, sp the Feret diameter perpendicular to s, and p the perimeter of the object.

When the measured object is either a perfect square, circle, triangle or ellipse, the values obtained by FeatureShape will be 1.0.

NOTE

This function uses chain codes. It expects each measured object to be compact, that is, to have only one chain code. Additional chain codes are ignored, meaning that non-compact objects are not measured properly. Take care in providing the correct connectivity value: if you object is compact only with 2-connectivity, this measure will fail if you call Measure with a value of 1 for the connectivity.

SEE ALSO

Measure

FeatureDimension, FeatureSize, FeatureCenter, FeatureGravity, FeatureMaximum, FeatureMinimum, FeatureFeret, FeatureMaxVal, FeatureMinVal, FeatureMean, FeatureStdDev, FeatureSum, FeatureMass, FeaturePerimeter, FeatureP2A, FeatureShape, FeatureSurfaceArea, FeatureAnisotropy2D, FeatureInertia, FeatureGinertia, FeatureMu, FeatureGmu, FeatureBendingEnergy, FeatureChainCodeBendingEnergy, FeatureExcessKurtosis, FeatureLongestChaincodeRun, FeatureOrientation2D, FeatureSkewness

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