TEXTURE

Python object: phenotypic.schema._texture.TEXTURE

Second-order texture features derived from the gray-level co-occurrence matrix (GLCM).

All features assume normalized GLCMs computed at one or more pixel offsets and averaged across directions unless otherwise noted. Values depend on quantization, window size, and scale; interpret ranges comparatively within the same imaging setup.

Category: Texture

Column label	Description
Texture_AngularSecondMoment	Angular second moment (energy / uniformity). Measures the degree of local homogeneity (Σ p(i,j)²). High values → uniform texture (e.g., smooth, yeast-like colonies with consistent mycelial density). Low values → heterogeneous surfaces (e.g., sectored, wrinkled, or mixed sporulation zones). Reflects colony surface regularity rather than brightness.
Texture_Contrast	Contrast (local intensity variation; Σ (i–j)² p(i,j)). High values indicate strong gray-level differences (e.g., sharply defined rings, radial sectors, raised or folded regions). Low values indicate gradual tonal changes or uniformly pigmented colonies. Quantifies visual roughness and zonation amplitude.
Texture_Correlation	Linear gray-level correlation between neighboring pixels. Positive, high values suggest structured spatial dependence (e.g., oriented radial hyphae or concentric patterns); near-zero values indicate uncorrelated, disordered growth (e.g., diffuse cottony mycelium). Sensitive to illumination gradients and directional GLCM computation.
Texture_HaralickVariance	GLCM variance (Σ (i–μ)² p(i,j)). Captures spread of co-occurring gray-level pairs, distinct from raw intensity variance. High values → complex, multi-zone textures with variable hyphal/spore densities. Low values → consistent gray-level relationships and simpler colony surfaces.
Texture_InverseDifferenceMoment	Homogeneity (Σ p(i,j) / (1 + (i–j)²)). High values → smooth, locally uniform textures (e.g., glabrous colonies, uniform aerial mycelium). Low values → abrupt gray-level changes (e.g., granular sporulation, wrinkled surfaces). Typically inversely correlated with Contrast.
Texture_SumAverage	Mean of gray-level sums (Σ k·p_{x+y}(k)). Reflects the average intensity combination of neighboring pixels. In fungal colonies, can loosely parallel mean colony brightness when illumination and exposure are controlled, but remains a second-order rather than first-order intensity metric.
Texture_SumVariance	Variance of gray-level sum distribution. High values → heterogeneous brightness zones (e.g., alternating dense/sparse or pigmented/non-pigmented regions). Low values → uniform tone across the colony. Often correlated with Contrast; use comparatively within one setup.
Texture_SumEntropy	Entropy of the gray-level sum distribution. High values → diverse brightness combinations and irregular zonation. Low values → repetitive or periodic brightness patterns (e.g., evenly spaced rings). Indicates spatial unpredictability of summed intensities.
Texture_Entropy	Global GLCM entropy (–Σ p(i,j)·log p(i,j)). Measures total texture disorder and information content. High values → complex, irregular colony surfaces (powdery, fuzzy, or sectored growth). Low values → simple, smooth, predictable patterns (glabrous or uniform colonies). Sensitive to gray-level quantization and image dynamic range.
Texture_DiffVariance	Variance of gray-level difference distribution. High values → mixture of smooth and textured regions (e.g., smooth margins with wrinkled centers). Low values → consistent edge content. Highlights heterogeneity in edge magnitude across the colony.
Texture_DiffEntropy	Entropy of gray-level difference distribution. High values → irregular, unpredictable intensity transitions (e.g., random sporulation or uneven mycelial networks). Low values → regular periodic transitions (e.g., concentric zonation). Reflects randomness of local contrast rather than its magnitude.
Texture_InfoCorrelation1	Information measure of correlation 1. Compares joint vs marginal entropies to quantify mutual dependence between gray levels. Positive values → structured, predictable textures (e.g., organized radial growth); near-zero → independence between adjacent regions. Direction of sign varies with implementation.
Texture_InfoCorrelation2	Information measure of correlation 2 (√[1 – exp(–2 (H_xy2–H_xy))]). Always ≥ 0. Values approaching 1 → strong spatial dependence and organized architecture (e.g., symmetric rings, radial structure). Values near 0 → random, independent patterns. Captures nonlinear organization missed by linear correlation.