Unmixing (segmentation)

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

Parameters

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.

Expression

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

Operators than can be used expressions include the data operators wNNN and bMMM for referring to wavelength bands, the range operator : used for averaging data, standard arithmetic (+,-,/,* …) and comparison operators (=,>,< …) as well as some mathematical functions ( …) and constants ( ).

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.

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

The Separate parameter defines how pixels that pass your segmentation threshold are grouped into distinct object samples.

Pixel Connectivity Rule

Breeze uses 8-connectivity. Pixels are considered connected if they touch horizontally, vertically, or diagonally on a single corner.

Parameter Options

1. Normal

• Behavior: Standard connected-component grouping.

• Result: Pixels touching by an edge or corner form a single object. Physically isolated clusters form separate objects.

2. Separate adjacent objects

• Behavior: Applies a distance transform to find the inner centers (geometric peaks) of pixel clusters, then splits them using a watershed-style growth algorithm.

• Best Used For: Round or spherical objects that are touching or overlapping.

• Limitation: Elongated, branched, or irregular shapes may be incorrectly split into multiple objects because the algorithm detects multiple internal peaks within a single physical item.

3. Merge all objects into one

• Behavior: Disregards spacing; combines all valid pixels across the entire image.

• Result: Evaluates the entire frame as one single object for collective regional analysis.

4. Merge all objects per row

• Behavior: Groups detected objects based on the spatial grid of their vertical center points ($Y$-coordinates).

• Result: All objects residing within the same horizontal row lane are merged into a single object.

5. Merge all objects per column

• Behavior: Groups detected objects based on the spatial grid of their horizontal center points ($X$-coordinates).

• Result: All objects residing within the same vertical column lane are merged into a single object.

Link

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.