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Classify ROIs

The Classify ROIs command takes segmentation-class objects produced by Extract ROIs and applies a set of shape and intensity filters. Objects that pass all filters are assigned to the target class; objects that fail are discarded.

Input Selection

ParameterDescription
Origin segmentationOne or more segmentation classes to process
Origin classAlternatively, input already-classified objects from named classes

Target Class

ParameterDescription
Target classThe named object class assigned to objects that pass all filters

Shape Filters

All shape-based filters accept –1 as “no limit” for the upper bound and 0 / –1 for “no lower limit”.

FilterDescription
Min area / Max areaObject area in px² (or µm² depending on Size unit)
Min circularity / Max circularityRange 0.0–1.0; 1.0 = perfect circle
Min solidity / Max solidityRatio of area to convex hull area (0–1)
Min aspect ratio / Max aspect ratioBounding box width / height ratio
Min eccentricity / Max eccentricityElongation from fitted ellipse (0 = circle, 1 = line segment)
Min Feret / Max FeretMaximum calliper (Feret) diameter
Allow edge touchingIf disabled, objects that touch the image border are discarded

Size unit

Shape filters that depend on physical size (area, Feret) can use:

  • Pixels (px) — absolute pixel count
  • Micrometres (µm) — converted using the pixel size from image metadata

Intensity Filters

FilterDescription
Min mean intensity / Max mean intensityAverage pixel intensity within the object
Intensity unitAbsolute (0–65535), Percent (0–100), or Relative (0–1)

Intensity is measured in the channel/plane configured in the input address. Set –1 to disable either bound.

Example: Spot detection

Min area: 3 px²
Max area: -1 (no upper limit)
Min circularity: 0.1
Max circularity: -1
Allow edge touching: true

This retains objects larger than 3 pixels with any shape, discarding single-pixel noise.