Original tone mapped image by iCAM06 {p=134, 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*): 51.0367
Mean of the chroma value (CIE L*a*b*): 10.4671
Image produced by the generic tone mapping operator:
(evalution of the fit via PSNR: PSNR = 27.5963dB)

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: 4.1684
Contrast: 0.35971
Low midtone range: 1.5378
High midtone range: 0.95954
Saturation: 0.69197
Frequencies: 1.351, 1.33, 1.479, 1.438, 1.384