deviation_image🔗
Short description🔗
deviation_image — Calculate the standard deviation of gray values within rectangular windows.
Signature🔗
deviation_image( image Image, out image ImageDeviation, extent.x Width, extent.y Height )
Description🔗
deviation_image 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. To better use the range of gray values
available in the output image, 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.
Attention🔗
deviation_image can be executed on OpenCL devices. As the same OpenCL
code is used, the same limitations as for mean_image apply. Since
deviation_image uses single precision floating point arithmetic
internally, the results may differ slightly from the CPU version.
Note that filter operators may return unexpected results if an image with a reduced domain is used as input. Please refer to the chapter Filters.
Execution information🔗
Execution information
-
Supports OpenCL compute devices.
-
Multithreading type: reentrant (runs in parallel with non-exclusive operators).
-
Multithreading scope: global (may be called from any thread).
-
Automatically parallelized on tuple level.
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Automatically parallelized on channel level.
-
Automatically parallelized on domain level.
Parameters🔗
Image (input_object) (multichannel-)image(-array) → object (byte* / int4* / real* / int2* / uint2*) *allowed for compute devices
Image for which the standard deviation is to be calculated.
ImageDeviation (output_object) image(-array) → object (byte / int4 / real / int2 / uint2)
Image containing the standard deviation.
Width (input_control) extent.x → (integer)
Width of the mask in which the standard deviation is calculated.
Default: 11
Suggested values: 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25
Restriction: 3 <= Width && odd(Width) && Width < width(Image) * 2
Height (input_control) extent.y → (integer)
Height of the mask in which the standard deviation is calculated.
Default: 11
Suggested values: 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25
Restriction: 3 <= Height && odd(Height) && Height < height(Image) * 2
Example🔗
(HDevelop)
read_image(Image,'fabrik')
dev_display(Image)
deviation_image(Image,Deviation,9,9)
dev_display(Image)
read_image(&Image,"fabrik")\;
disp_image(Image,WindowHandle)\;
deviation_image(Image,&Deviation,9,9)\;
disp_image(Deviation,WindowHandle)\;
Result🔗
deviation_image returns 2 (H_MSG_TRUE) if all parameters are correct.
If the input is empty the behavior can be set via
set_system('no_object_result',<Result>). If
necessary, an exception is raised.
Combinations with other operators🔗
Combinations
Possible successors
Alternatives
See also
Module🔗
Foundation