Original tone mapped image by iCAM06 {p=536, ct=0.65}:

Histogram of the tone mapped image:

Image statistics of the tone-mapped image:

Median percentile of the lightness (CIE L*a*b*): 59.503
Mean of the chroma value (CIE L*a*b*): 6.6525
Image produced by the generic tone mapping operator:
(evalution of the fit via PSNR: PSNR = 22.9314dB)

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: -0.021292
Contrast: 1.1933
Low midtone range: 8.401
High midtone range: 3.8145
Saturation: 0.18504
Frequencies: 1.053, 1.029, 1.033, 1.022, 0.994