DIPlib Documentation - ©1995-2014 Quantitative Imaging Group, Delft University of Technology.

FeatureFeret

Measure the object's Feret diameters

SYNOPSIS

#include "dip_measurement.h"

dip_int dip_FeatureFeretID ( void )

OUTPUT DATA TYPE

dip_FloatArray

FUNCTION

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

This function measures the Feret maximum and minimum diameters of an object. The Feret diameters are found by a "rotating caliper" algorithm on the convex hull polygon, see ConvexHullGetFeret. This function supports 2D images only.

The values returned are:

FeretMaxThe widest projection of the object
FeretMinThe narrowest projection of the object
FeretPerpMinThe width of the projection perpendicular to "FeretMin"
FeretMaxAngThe angle of the projection for "FeretMax"
FeretMinAngThe angle of the projection for "FeretMin"

NOTE

If any physical dimensions are passed to this function through Measure, only the sample distance along the first dimension is used. All other dimensions are assumed to be sampled the same way. This produces incorrect results for anisotropically sampled images.

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.

NOTE

In DIPlib version 2.3 and earlier, this measure was computed from the chain code directly, using the function ChainCodeGetFeret.

SEE ALSO

Measure, ImageChainCode, ChainCodeConvexHull, ConvexHullGetFeret

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