Table 2. Segmentation strategies used by the competing methods.

Principle, Feature, and Methodology used in the segmentation phase of the competing algorithms (following the taxonomy shown in Fig. 3) along with the preprocessing and postprocessing strategies employed.

Algorithm	Preprocessing	Principle	Feature	Methodology	Postprocessing
COM-US	Noise suppression Intensity normalization	Homogeneity	Intensity	Thresholding	Size filtering
CUL-UK	Noise suppression Illumination correction	Homogeneity	Intensity	Thresholding	Size filtering
CUNI-CZ	Noise suppression	Homogeneity	Intensity	Thresholding	Size filtering Cluster separation
FR-Be-GE	Intensity normalization Illumination correction	Homogeneity Boundary	Intensity	Energy minimization	Size filtering Hole filling
FR-Ro-GE	Intensity normalization Illumination correction	Homogeneity	Texture descriptor	Machine learning	None
HD-Har-GE	Noise suppression Intensity clipping	Homogeneity	Intensity	Thresholding	Hole filling Cluster separation
HD-Hau-GE	None	Homogeneity	Texture descriptor	Machine learning	Size filtering
IMCB-SG (1)	Noise suppression Illumination correction	Homogeneity	Intensity	Thresholding	Size filtering Cluster separation
IMCB-SG (2)	Image resampling Noise suppression Illumination correction	Homogeneity	Intensity	Thresholding	Size filtering Cluster separation
KIT-GE	Noise suppression	Homogeneity	Local descriptor	Thresholding	None
KTH-SE (1)	Intensity normalization Noise suppression Illumination correction	Homogeneity	Intensity	Thresholding	Size filtering Hole filling Cluster separation
KTH-SE (2)	Intensity normalization Noise suppression Illumination correction	Homogeneity	Intensity	Thresholding	Size filtering Hole filling Cluster separation
KTH-SE (3)	Intensity normalization Illumination correction	Homogeneity	Local descriptor	Thresholding	Boundary Refinement
KTH-SE (4)	Intensity normalization Noise suppression	Boundary	Intensity	Thresholding	Size filtering Region merging
LEID-NL	Noise suppression	Homogeneity	Intensity	Energy minimization	Cluster separation
MU-CZ	Noise suppression	Homogeneity	Intensity	Energy minimization	Cluster separation
NOTT-UK	Intensity normalization	Homogeneity	Intensity	Thresholding	None
PAST-FR	Intensity normalization Noise suppression	Homogeneity Boundary	Intensity	Energy minimization	None
UP-PT	Image subsampling Noise suppression	Homogeneity Peak	Intensity	Thresholding	Boundary refinement
UPM-ES	Noise suppression	Homogeneity	Intensity	Thresholding	Size filtering Hole filling Boundary refinement
UZH-CH	Intensity normalization Noise suppression Illumination correction	Homogeneity	Intensity	Region growing	Size filtering Hole filling