# 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:

Equals -

`=`

And -

`&`

Or -

`|`

Less than -

`<`

Less or equal -

`<=`

Larger -

`>`

Larger or equal -

`>=`

Different from -

`!=`

**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`

#### Shrink

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

#### Separate

Select one of the options below

**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.