Intensity features

Description

Intensity features quantify the pixel/voxel value distributions within segmented objects. these measurements capture both overall intensity levels and spatial intensity patterns.

Features extracted

Location-based intensity

Feature

description

CM.X / CM.Y / CM.Z

average intensity-weighted coordinates in each spatial dimension

CMI.X / CMI.Y / CMI.Z

center of mass intensity in each spatial dimension

I.X / I.Y / I.Z

integrated intensity along each axis

MAX.X / MAX.Y / MAX.Z

coordinates of maximum intensity

Statistical measures

Feature

description

MEAN.INTENSITY

average intensity within object

MEDIAN.INTENSITY

median intensity value

MAX.INTENSITY

maximum intensity value

MIN.INTENSITY

minimum intensity value

STD.INTENSITY

standard deviation of intensity

MAD.INTENSITY

median absolute deviation

LOWER.QUARTILE.INTENSITY

25th percentile

UPPER.QUARTILE.INTENSITY

75th percentile

Edge-based measurements

Feature

description

INTEGRATED.INTENSITY.EDGE

sum of edge pixel intensities

MEAN.INTENSITY.EDGE

average edge intensity

MAX.INTENSITY.EDGE

maximum edge intensity

MIN.INTENSITY.EDGE

minimum edge intensity

STD.INTENSITY.EDGE

standard deviation of edge intensities

EDGE.COUNT

number of edge voxels

Other measurements

Feature

description

VOLUME

object volume (included for reference)

DIFF.X / DIFF.Y / DIFF.Z

spatial intensity gradient in each dimension

MASS.DISPLACEMENT

distance between geometric and intensity centers

Calculation method

Intensity features are computed as follows:

  1. Segmentation masking: apply object masks to isolate pixel/voxel values

  2. Statistical computation: calculate mean, median, max, min, std, etc.

  3. Spatial analysis: determine intensity-weighted coordinates and gradients

  4. Edge detection: identify edge pixels/voxels and compute edge statistics

Applications

Intensity features are useful for:

  • Quantifying fluorescence levels within cellular structures

  • Detecting changes in protein expression

  • Characterizing subcellular localization patterns

  • Identifying phenotypic alterations due to treatments