Statistical measure: the indicator to calculate, available are
- INTENSITY_MEAN: average intensity in the image
- INTENSITY_MAX: maximal intensity in the image
- INTENSITY_MIN: minimal intensity in the image
- INTENSITY_VARIANCE: intensity variance in the image
- INTENSITY_STDDEV: standard deviation of the image intensity
- INTENSITY_ENTROPY: entropy of image intensities
- HISTO_UNIFORMITY: uniformity of intensity
- HISTO_SKEWNESS: skewness of intensity distribution, third moment