Texture Discretization Sensitivity

Sweep GLCM bin width on a synthetic textured lesion and watch contrast, energy and entropy shift by large factors even though the tissue never changes.

GLCM
discretization
IBSI
texture
gray-level binning

Gray levels used

18.000

Contrast

4.701

Energy

0.016

Entropy

4.420

Discretized phantom

18 gray levels

Continuous phantom (reference)

native intensity units

Feature value vs. bin width

ContrastEntropyEnergy ×20

Sensitivity across the bin-width sweep

Coefficient of variation across the sweep — contrast: 1.64, energy: 1.10, entropy: 0.53.
Bin width	Gray levels	Contrast	Energy	Entropy	Homogeneity
1.000	64.000	48.862	0.002	6.783	0.252
2.000	44.000	23.398	0.003	6.140	0.315
3.000	30.000	11.165	0.006	5.391	0.389
5.000	18.000	4.701	0.016	4.420	0.493
8.000	12.000	2.287	0.039	3.519	0.598
12.000	9.000	1.254	0.080	2.812	0.692
16.000	7.000	0.937	0.130	2.312	0.750
20.000	6.000	0.964	0.193	1.965	0.790
25.000	5.000	0.696	0.271	1.666	0.829
32.000	4.000	0.879	0.303	1.445	0.837

Texture features are not properties of the tumor alone

The lesion never changes across this sweep — only the discretization does. Contrast and entropy shift by large factors as bin width changes because they are computed on the quantized image, not the physical intensity field. IBSI-style reporting requires fixing the bin width (or the number of gray levels) and stating it explicitly; comparing "contrast" values computed at different bin widths compares different quantities that happen to share a name.

Preparing the simulation…