gray_erosion_shapegray_erosion_shapeGrayErosionShapegray_erosion_shapeGrayErosionShapeGrayErosionShape (Operator)

Name

gray_erosion_shapegray_erosion_shapeGrayErosionShapegray_erosion_shapeGrayErosionShapeGrayErosionShape — Determine the minimum gray value within a selected mask.

Signature

Description

gray_erosion_shapegray_erosion_shapeGrayErosionShapegray_erosion_shapeGrayErosionShapeGrayErosionShape calculates the minimum gray value of the input image ImageImageImageImageImageimage within a mask of shape MaskShapeMaskShapeMaskShapeMaskShapeMaskShapemaskShape, vertical size MaskHeightMaskHeightMaskHeightMaskHeightMaskHeightmaskHeight and horizontal size MaskWidthMaskWidthMaskWidthMaskWidthMaskWidthmaskWidth for each image point. The resulting image is returned in ImageMinImageMinImageMinImageMinImageMinimageMin.

If the parameters MaskHeightMaskHeightMaskHeightMaskHeightMaskHeightmaskHeight or MaskWidthMaskWidthMaskWidthMaskWidthMaskWidthmaskWidth 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 ImageImageImageImageImageimage is transformed with both the next larger and the next smaller odd mask size, and the output image ImageMinImageMinImageMinImageMinImageMinimageMin is interpolated from the two intermediate images. Therefore, note that gray_erosion_shapegray_erosion_shapeGrayErosionShapegray_erosion_shapeGrayErosionShapeGrayErosionShape returns different results for mask sizes of, e.g., 4 and 4.0!

In case of the values 'rhombus' and 'octagon' for the MaskShapeMaskShapeMaskShapeMaskShapeMaskShapemaskShape control parameter, MaskHeightMaskHeightMaskHeightMaskHeightMaskHeightmaskHeight and MaskWidthMaskWidthMaskWidthMaskWidthMaskWidthmaskWidth must be equal. The parameter value 'octagon' for MaskShapeMaskShapeMaskShapeMaskShapeMaskShapemaskShape 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_erosion_shapegray_erosion_shapeGrayErosionShapegray_erosion_shapeGrayErosionShapeGrayErosionShape 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_erosion_shapegray_erosion_shapeGrayErosionShapegray_erosion_shapeGrayErosionShapeGrayErosionShape 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.

Parallelization

• 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.
• Automatically parallelized on channel level.
• Automatically parallelized on domain level.

Parameters

Result

gray_erosion_shapegray_erosion_shapeGrayErosionShapegray_erosion_shapeGrayErosionShapeGrayErosionShape returns 2 (H_MSG_TRUE) if all parameters are correct.

Alternatives

gray_erosiongray_erosionGrayErosiongray_erosionGrayErosionGrayErosion, gray_erosion_rectgray_erosion_rectGrayErosionRectgray_erosion_rectGrayErosionRectGrayErosionRect

See also

gray_opening_shapegray_opening_shapeGrayOpeningShapegray_opening_shapeGrayOpeningShapeGrayOpeningShape, gray_closing_shapegray_closing_shapeGrayClosingShapegray_closing_shapeGrayClosingShapeGrayClosingShape, gray_skeletongray_skeletonGraySkeletongray_skeletonGraySkeletonGraySkeleton

Module

Foundation