# Overlap Measures

Compute Jaccard overlap, Dice coefficient, volume similarity, false negative error and false positive error similarity of two or more binary masks.

The measures are defined as follows:

$$\textrm{Jaccard} = \displaystyle 2\frac{S \cap T}{S\cup T}$$

$$\textrm{Dice} = \displaystyle 2\frac{S \cap T}{S + T} = \frac{2\times Jaccard}{1+Jaccard}$$

$$\textrm{Volume Similarity} = 2 \displaystyle \frac{S-T}{S+T}$$

$$\textrm{False Negative Error} = \displaystyle \frac{T \setminus \!\!S}{S}$$

$$\textrm{False Positive Error} = \displaystyle \frac{S \setminus \!\!T}{T}$$

## Inputs

At least two binary masks of the same size.

Type: Image4DBool, Required, Multiple (Minimum = 2)

## Outputs

#### Measures

A Data Table with seven columns: Mask 1, Mask 2, Dice, Jaccard, Volume Similarity, False Negative Error, False Positive Error

Type: DataCollection

## Settings

#### Slicewise Boolean

Perform the analysis slice by slice. Each slice will result in one row in the output result data table.

#### Slice Direction Selection

If slicewise analysis is selected this specifies the orientation of slices. E.g. if slice orientation is XY, slice interpolation will be in the z-direction.

Values: XY, XZ, YZ