gray_dilation_shape🔗
Short description🔗
gray_dilation_shape — Determine the maximum gray value within a selected mask.
Signature🔗
gray_dilation_shape( image Image, out image ImageMax, extent.y MaskHeight, extent.x MaskWidth, string MaskShape )
Description🔗
gray_dilation_shape calculates the maximum gray value of the input
image Image within a mask of shape MaskShape,
vertical size MaskHeight and horizontal size MaskWidth
for each image point.
The resulting image is returned in ImageMax.
If the parameters MaskHeight or MaskWidth are of the
type integer and are even, they are changed to the next larger odd value.
In contrast, if at least one of the two parameters is of the type float, the
input image Image is transformed with both the next larger and
the next smaller odd mask size, and the output image ImageMax is
interpolated from the two intermediate images. Therefore, note that
gray_dilation_shape returns different results for mask sizes of,
e.g., 4 and 4.0!
In case of the values
‘rhombus’ and ‘octagon’ for the MaskShape control parameter,
MaskHeight and MaskWidth must be equal. The parameter
value ‘octagon’ for MaskShape denotes an equilateral octagonal
mask which is a suitable approximation for a circular structure.
At the border of the image the gray values are mirrored.
Attention🔗
Note that gray_dilation_shape requires considerably more time for
mask sizes of type float than for mask sizes of type integer. This is
especially true for rectangular masks with different width and height!
gray_dilation_shape can be executed on OpenCL devices. In case of
mask sizes of type float the result can vary slightly from the CPU as the
interpolation is calculated in single precision on the OpenCL device.
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).
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Automatically parallelized on tuple level.
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Automatically parallelized on channel level.
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Automatically parallelized on domain level.
Parameters🔗
Image (input_object) (multichannel-)image(-array) → object (byte* / uint2*) *allowed for compute devices
Image for which the maximum gray values are to be calculated.
ImageMax (output_object) (multichannel-)image(-array) → object (byte / uint2)
Image containing the maximum gray values.
MaskHeight (input_control) extent.y → (real / integer)
Height of the filter mask.
Default: 11
Suggested values: 3, 5, 7, 9, 11, 13, 15
Value range: 1.0 ≤ MaskHeight
MaskWidth (input_control) extent.x → (real / integer)
Width of the filter mask.
Default: 11
Suggested values: 3, 5, 7, 9, 11, 13, 15
Value range: 1.0 ≤ MaskWidth
MaskShape (input_control) string → (string)
Shape of the mask.
Default: 'octagon'
List of values: 'octagon', 'rectangle', 'rhombus'
Result🔗
gray_dilation_shape returns 2 (H_MSG_TRUE) if all
parameters are correct.
Combinations with other operators🔗
Module🔗
Foundation