DIPlib Documentation - ©1995-2013 Quantitative Imaging Group, Delft University of Technology.

# FeatureRadius

Measure the object's radius statistics

## SYNOPSIS

`#include "dip_measurement.h"`

dip_int dip_FeatureRadiusID ( void )

## OUTPUT DATA TYPE

`dip_FloatArray`

## FUNCTION

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

This function obtains various statistics from the distance of each boundary pixel to the object's centre. The centre of the object is obtained from the centre of gravity of the border pixels only. See `ChainCodeGetRadius` for more information. This function supports 2D images only.

The values returned are:

RadiusMax | The maximum radius
RadiusMean | The average radius
RadiusMin | The minimum radius
RadiusStD | The standard deviation of the radii

## 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.

## SEE ALSO

`Measure`, `ImageChainCode`, `ChainCodeGetRadius`

`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`