Original tone mapped image by PTMO {g=2.8, c=1.8}:

Histogram of the tone mapped image:

Image statistics of the tone-mapped image:

Median percentile of the lightness (CIE L*a*b*): 54.8673
Mean of the chroma value (CIE L*a*b*): 8.4711
Image produced by the generic tone mapping operator:
(evalution of the fit via PSNR: PSNR = 36.9642dB)

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: 4.0827
Contrast: 0.99744
Low midtone range: 5.1323
High midtone range: 1.4884
Saturation: 0.60787
Frequencies: -0.101, 0.68, 1.045, 1.051, 1.024