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
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 (input_object) |
region(-array) -> object |
Regions the features of which are to be calculated. |
Image (input_object) |
image -> object : byte / int1 / int2 / int4 / real |
Gray value image. |
Mean (output_control) |
real(-array) -> real |
Mean gray value of a region. |
Deviation (output_control) |
real(-array) -> real |
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 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.