# Constrained Spectral Unmixing (segmentation)

Use the spectral information from pure samples in the *endmembers *to create objects from the expression criteria for segmentation.

### Parameters

#### Expression

Write in the expression you want to apply. The following comparators can be used for the expression:

Standard arithmetic (`+`

,`-`

,`/`

,`*`

…) and comparison operators (`=`

,`>`

,`<`

…) as well as some mathematical expressions (…) and constant values can be used in expressions.

**Example: **`(Filename of end member 1) > 1 | (Filename of end member 2) < 0.5`

#### Method

Use one of the following regression methods to compare the end members spectrum to the measurements:

**None Negative Least Squares****Sum To One Least Squares**

#### Scatter correction

Select one of the options below

**None**No scatter correction applied.

**Baseline**A constant scatter correction is applied.

**Slope**A linear scatter correction is applied.

**Parabola**A quadratic scatter correction is applied.

#### Expression (Optional)

To include extra expression.

#### Range

Write in the wavelength range to use. If left empty all wavelengths are included.

#### End Members (1-10)

Select files containing End members for each pure sample.

#### Min area

The minimum number of pixels for an object to be included.

#### Max area

The maximum number of pixels for an object to be included.

If 0 no maximum area is defined.

#### Object filter

Use an expression to further exclude unwanted objects based on shape.

Properties that can be used for the Expression:

`Area`

`Length`

`Width`

`Circumference`

`Regularity`

`Roundness`

`Angle`

`D1`

`D2`

`X`

`Y`

`MaxBorderDistance`

`BoundingBoxArea`

For details on each available property see: Object properties Details

#### Shrink

Takes away numbers of pixels at the borders of the objects included in images.

#### Separate

**Normal**Can have both separated and combined objects.

**Separate adjacent objects**All objects are defined separately.

**Merge all objects into one**All objects are defined as one.

**Merge all objects per row**All objects per row segmentation are defined as one.

**Merge all objects per column**All objects per column segmentation are defined as one.

#### Link

Only visible when applicable

Link output objects from two or more segmentations to top segmentation. Descriptors can then be added to the common object output and will be calculated for objects from all segmentations.

The segmentations must be at same level to be available for linking.