Table 1.

Measurement evaluation of contrast, CII, and SNR for Figure 4.

Method	Contrast	CII	SNR
Original image	0.0503	1.0000
HE	0.1607	2.5140	14.1344
AHE	0.0756	3.5981	4.0076
Nonlinear method based on Laplace pyramid	0.1230	4.0467	6.9851
Wavelet method	0.1137	5.4673	18.1565
The proposed method	0.2677	14.5514	12.9723