Original tone mapped image by PTMO {g=2.2, c=0.6}:

Histogram of the tone mapped image:

Image statistics of the tone-mapped image:

Median percentile of the lightness (CIE L*a*b*): 31.3329
Mean of the chroma value (CIE L*a*b*): 5.5905
Image produced by the generic tone mapping operator:
(evalution of the fit via PSNR: PSNR = 35.9188dB)

Fitted tone curve of the generic tone mapping operator,
compared to the luminance compression done by the tone mapping operator:

Fitted parameters of the generic tmo:

Exposure: 0.70488
Contrast: 1.7108
Low midtone range: 4.2308
High midtone range: 9.7533
Saturation: 0.26366
Frequencies: 0.716, 0.949, 0.991, 0.999, 0.995