Original tone mapped image by iCAM06 {p=134, ct=0.5}:

Histogram of the tone mapped image:

Image statistics of the tone-mapped image:

Median percentile of the lightness (CIE L*a*b*): 57.2935
Mean of the chroma value (CIE L*a*b*): 12.4947
Image produced by the generic tone mapping operator:
(evalution of the fit via PSNR: PSNR = 26.7503dB)

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: 3.9037
Contrast: 0.31539
Low midtone range: 1.2818
High midtone range: 1.305
Saturation: 0.7492
Frequencies: 1.728, 1.644, 1.762, 1.66, 1.57