Original tone mapped image by Camera {x=middle, c=1}:

Histogram of the tone mapped image:

Image statistics of the tone-mapped image:

Median percentile of the lightness (CIE L*a*b*): 46.2595
Mean of the chroma value (CIE L*a*b*): 27.94
Image produced by the generic tone mapping operator:
(evalution of the fit via PSNR: PSNR = 35.5537dB)

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: 2.0787
Contrast: 1.4037
Low midtone range: 1.3585
High midtone range: 2.0967
Saturation: 0.42281
Frequencies: 0.053, 0.694, 1.023, 1.023, 1.028