Original tone mapped image by DATMO {e=1, 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*): 50.957
Mean of the chroma value (CIE L*a*b*): 9.199
Image produced by the generic tone mapping operator:
(evalution of the fit via PSNR: PSNR = 36.2992dB)

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: 4.189
Contrast: 1.2439
Low midtone range: 1.5591
High midtone range: 0.75333
Saturation: 0.82996
Frequencies: -0.014, 0.726, 0.986, 0.988, 0.958