Original tone mapped image by PTMO {g=2.2, c=1}:

Histogram of the tone mapped image:

Image statistics of the tone-mapped image:

Median percentile of the lightness (CIE L*a*b*): 37.4875
Mean of the chroma value (CIE L*a*b*): 26.0706
Image produced by the generic tone mapping operator:
(evalution of the fit via PSNR: PSNR = 39.2759dB)

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: 2.2167
Contrast: 1.5957
Low midtone range: 2.2624
High midtone range: 1.1076
Saturation: 0.43824
Frequencies: -0.004, 0.64, 1.043, 1.02, 1.017