Features

Several Feature types are defined these include: 1. Intrinsic Features 2. Associative Features

Contents 1 Intrinsic Features 1.1 Volume 1.2 Integrated Intensity 1.3 Eccentricity 1.4 Elongation 1.5 Orientation 1.6 Bounding Box Volume 1.7 Sum 1.8 Mean 1.9 Median 1.10 Minimum 1.11 Maximum 1.12 Sigma 1.13 Variance 1.14 Radius Variation 1.15 Skew 1.16 Energy 1.17 Entropy 1.18 Surface Gradient 1.19 Interior Gradient 1.20 Interior Intensity 1.21 Surface Intensity 1.22 Intensity Ratio 1.23 Shared Boundary 1.24 Surface Area 1.25 Shape

Intrinsic Features

These features can be calculated with two input images (Data Image and Label Image). They are most commonly used for blob-like regions, such as nuclei.

Volume

Number of voxels in the object (Dirk)

Integrated Intensity

Sum of the intensities of all voxels in the object (Dirk)

Eccentricity

Ratio of the distance between the foci to the length of the major axis (2D?) (Dirk)

Elongation

Major axis length over minor axis length (2D?) (Dirk)

Orientation

Angle between major axis and origin (2D) (Dirk)

Bounding Box Volume

Number of voxels in bounding box of object (Dirk)

Sum

Same as integrated intensity (ITK statistics)

Mean

Average intensity of voxels in the object (ITK statistics)

Median

Middle intensity of voxels in the object (ITK statistics)

Minimum

Minimum intensity of voxels in the object (ITK statistics)

Maximum

Maximum intensity of voxels in the object (ITK statistics)

Sigma

Standard deviation of intensity of voxels in the object (ITK statistics)

Variance

Variance of intensity of voxels in the object (ITK statistics)

Radius Variation

Standard deviation of distance from surface voxels to centroid (Isaac)

Skew

Skew of the normalized intensity histogram (Isaac) (See Supplement B2)

Energy

Energy of the normalized intensity histogram (Isaac) (See Supplement B2)

Entropy

Entropy of the normalized intensity histogram (Isaac) (See Supplement B2)

Surface Gradient

Average of surface gradients (Isaac)

Interior Gradient

Average of interior gradients (Isaac)

Interior Intensity

Average of interior intensities (Isaac)

Surface Intensity

Average of surface intensities (Isaac)

Intensity Ratio

Ratio of surface intensity to interior intensity (Isaac)

Shared Boundary

Ratio of surface area that touches another object to total surface area (Isaac)

Surface Area

Number of voxels on surface of the object (Isaac)

Shape

Ratio of surface voxels to total voxels - compactness or thinness of object (Isaac) (See Supplement B2)