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*): 83.2612
Mean of the chroma value (CIE L*a*b*): 7.5459
Image produced by the generic tone mapping operator:
(evalution of the fit via PSNR: PSNR = 39.0946dB)

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: 3.6483
Contrast: 1.5355
Low midtone range: 1.3481
High midtone range: 0.91975
Saturation: 0.44279
Frequencies: -0.087, 0.78, 0.997, 0.994, 0.988