deviation__ ( Image : ImageDeviation : Width, Height : )

Calculate the standard deviation of gray values within a rectangular window.

deviation__ calculates the standard deviation of gray values in the image Image within a rectangular mask of size (Height, Width). The resulting image is returned in ImageDeviation. For byte images, the result is multiplied by 2. If the parameters Height and Width are even, they are changed to the next larger odd value. At the image borders the gray values are mirrored.


Parameters

Image (input_object)
image(-array) -> object : byte / int4 / real
Image for which the standard deviation is to be calculated.

ImageDeviation (output_object)
image(-array) -> object : byte / int4 / real
Image containing the standard deviation.

Width (input_control)
extent.x -> integer
Width of the mask in which the standard deviation is calculated.
Default value: 11
List of values: 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25
Restriction: (3 <= Width) && odd(Width)

Height (input_control)
extent.y -> integer
Height of the mask in which the standard deviation is calculated.
Default value: 11
List of values: 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25
Restriction: (3 <= Height) && odd(Height)


Example
read_image(:Image:'fabrik':) >
disp_image(Image:::)
deviation__(Image:Deviation:9,9:) >
disp_image(Deviation:::).

Result

deviation__ returns TRUE if all parameters are correct. If the input is empty the behaviour can be set via set_system(::'no_object_result',<Result>:). If necessary, an exception is raised.


Possible Successors

disp_image


Alternatives

entropy1__, entropy2__


See also

convol__, laws_byte, intensity__



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