Mathematical morphology-based approach to the enhancement of morphological features in medical images

Table 1 Measured CIR values for ROIs including phantom features

ROI	Measured CIR values for various image enhancement methods
	Proposed	HE	LCS	USM	MSR	CLAHE
R ₁	14.8291	1.3832	0.0337	2.1091	0.5043	3.8390
R ₂	199.3442	9.8188	0.0330	1.9410	0.5647	11.7008
R ₃	229.1748	8.3543	0.0903	2.0105	0.3285	12.6779

Proposed method, histogram equalization (HE), linear contrast stretching (LCS), unsharp masking (USM), multiscale retinex (MSR), and contrast limited adaptive histogram equalization (CLAHE).