Table 4. PSNR Results for synthetic experiment.

Method	PSNR(dB)
	β = 0.1	β = 0.2	β = 0.3	β = 0.4	β = 0.5	β = 0.6	β = 0.7	β = 0.8	β = 0.9
Baseline	22.64	24.11	28.64	28.91	31.32	32.19	31.97	33.18	34.17
SRF	25.52	34.91	37.64	34.72	38.26	36.77	35.97	36.39	36.03
NCDF	19.03	20.70	23.65	24.07	24.95	25.88	24.77	25.66	26.36
DiffusionO	25.45	25.45	28.34	28.12	32.17	33.43	32.31	32.75	33.94
Molecular	21.95	21.95	25.08	26.99	29.92	28.89	29.38	28.48	28.37
MSVST	28.60	28.60	28.42	28.70	28.48	28.89	28.40	28.48	28.56
VWNF	31.12	33.47	33.11	32.17	33.94	34.22	34.66	33.91	35.06
PURELET	23.61	24.91	27.62	27.07	27.99	30.15	28.57	27.01	28.92

Using a photon-conversion factor of (β) 0.5, optimal parameters were found via grid search to produce the highest PSNR, using Eq. 24, for all methods. This table summarizes the PSNR values of those parameters applied for the remaining photo-conversion factors. Highest values are shown in bold and the Baseline refers to the noisy synthetic phantom.