Table 1.

The RMSE values obtained by the four baseline correction methods.

Methods	Baseline Type (Low Noise)				Baseline Type (High Noise)
	Linear		Sine		Linear		Sine
	Optimal Parameters	RMSE	Optimal Parameters	RMSE	Optimal Parameters	RMSE	Optimal Parameters	RMSE
I-ModPoly 1	order 5 = 6	0.1043	order = 6	0.0790	order = 5	0.1315	order = 6	0.1164
MPLS 2	λ 6 = 108 w 7 = 70	0.0131	λ = 107.6 w = 80	0.0148	λ = 108.8 w = 60	0.0764	λ = 107.6 w = 70	0.0312
IA 3	T 8 = 10−2.2	0.1128	T = 10−2.2	0.0831	T = 10−2	0.1907	T = 10−2	0.1641
erPLS 4	-	0.0061	-	0.0036	-	0.0098	-	0.0109

^1. I-ModPoly—improved modified multi-polynomial fitting method; ^2. MPLS—morphological weighted penalized least squares method; ^3. IA—iterative averaging method; ^4. erPLS—the proposed method; ^5. order—polynomial order of the I-ModPoly method; ^6. λ—smoothness parameter of the MPLS method; ^7. w—half window parameter of the MPLS method; ^8. T—threshold parameter of the IA method.