intensity — Calculate the mean and deviation of gray values.
The operator intensity calculates the mean and the deviation of the gray values in the input image within Regions. If R is a region, p a pixel from R with the gray value g(p) and F the plane (F = |R|), the features are defined by:
---- \ Mean = / g(p) ---- p in R ----------- F ----------------------- | ---- | 1 \ 2 Deviation = | - / (g(p)-Mean) \ | F ---- \| p in R
Note that the operator intensity only considers the given Regions and ignores any previously set domain of the input image Image. The calculation of Deviation does not follow the usual definition if the region of the image contains only one pixel. In this case 0.0 is returned.
Regions in which the features are calculated.
Gray value image.
Mean gray value of a region.
Deviation of gray values within a region.
If F is the area of the region, the runtime complexity is O(F).
The operator intensity returns the value 2 (H_MSG_TRUE). The behavior in case of empty input (no input images available) is set via the operator set_system(::'no_object_result',<Result>:), the behavior in case of empty region is set via set_system(::'empty_region_result',<Result>:). If necessary an exception is raised.
mean_image, mean_image, gray_histo, gray_histo_abs