Texture features

Description

Texture features quantify spatial patterns and local intensity variations within segmented objects. these features are computed from the gray-level co-occurrence matrix (GLCM).

Calculation method

Texture features are derived from the gray-level co-occurrence matrix (GLCM), which captures the frequency of intensity pair relationships at specified offsets.

Parameters

• Gray levels: 256 (quantization of intensity values)

• Offset: 1 voxel (distance for co-occurrence pairs)

These parameters can be adjusted to capture texture patterns at different scales.

Features extracted

Texture feature measurements

Feature	description	range	low value indicates	high value indicates
Angular.second.moment	textural uniformity / energy	[0, 1]	heterogeneous, varied texture (many different patterns)	uniform, homogeneous texture (repetitive patterns)
Contrast	local variation in intensity	[0, ∞)	smooth, low contrast (blurred edges, gradual transitions)	sharp edges, high contrast (crisp boundaries, distinct structures)
Correlation	linear dependency of neighboring gray levels	[-1, 1]	uncorrelated, random texture (independent pixel intensities)	correlated texture (organized structures, smooth gradients)
Variance	spread of GLCM intensity values	[0, (255)²]	narrow intensity range (uniform brightness)	wide intensity range (high dynamic range)
Inverse.difference.moment	local homogeneity	[0, 1]	inhomogeneous (varied local intensities)	homogeneous (similar neighboring pixels)
Sum.average	weighted mean intensity	[0, 2(255)]	dark co-occurrence (low signal, dim staining)	bright co-occurrence (strong signal, bright staining)
Sum.variance	variance of combined intensities	[0, ∞)	consistent combined intensities	wide range of intensity sums
Sum.entropy	randomness in intensity sums	[0, log₂(511)]	ordered, predictable sum patterns	random, disordered intensity sums
Entropy	overall texture complexity	[0, log₂(65536)]	simple, ordered texture (smooth regions, uniform areas)	complex, random texture (highly textured, irregular patterns)
Difference.variance	variance in intensity differences	[0, (65536)]	consistent contrast throughout	variable local contrast (mixed smooth/textured regions)
Difference.entropy	randomness in intensity differences	[0, log₂(256)]	smooth transitions (gradual edges)	irregular transitions (fragmented structures, noisy edges)
Info.measure.corr.1	mutual information correlation 1	[-1, 1]	weak correlation (think random noise)	strong nonlinear correlation (organized patterns)
Info.measure.corr.2	mutual information correlation 2	[0, 1]	low mutual information (uncorrelated texture)	high mutual information (highly organized texture)

Note: 255 is used but can be replaced with ng where: ng represents the number of gray levels (256 in this implementation).