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*): 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 = 22.9306dB)

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: -0.02029
Contrast: 1.2385
Low midtone range: 10.0239
High midtone range: 6.6241
Saturation: 0.18482
Frequencies: 1.061, 1.028, 1.034, 1.022, 1.005