gray_erosion_shapegray_erosion_shapeGrayErosionShapeGrayErosionShape (Operator)

Name

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

Signature

Description

gray_erosion_shapegray_erosion_shapeGrayErosionShapeGrayErosionShapeGrayErosionShape calculates the minimum gray value of the input image ImageImageImageImageimage within a mask of shape MaskShapeMaskShapeMaskShapeMaskShapemaskShape, vertical size MaskHeightMaskHeightMaskHeightMaskHeightmaskHeight and horizontal size MaskWidthMaskWidthMaskWidthMaskWidthmaskWidth for each image point. The resulting image is returned in ImageMinImageMinImageMinImageMinimageMin.

If the parameters MaskHeightMaskHeightMaskHeightMaskHeightmaskHeight or MaskWidthMaskWidthMaskWidthMaskWidthmaskWidth 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 ImageImageImageImageimage is transformed with both the next larger and the next smaller odd mask size, and the output image ImageMinImageMinImageMinImageMinimageMin is interpolated from the two intermediate images. Therefore, note that gray_erosion_shapegray_erosion_shapeGrayErosionShapeGrayErosionShapeGrayErosionShape returns different results for mask sizes of, e.g., 4 and 4.0!

In case of the values 'rhombus' and 'octagon' for the MaskShapeMaskShapeMaskShapeMaskShapemaskShape control parameter, MaskHeightMaskHeightMaskHeightMaskHeightmaskHeight and MaskWidthMaskWidthMaskWidthMaskWidthmaskWidth must be equal. The parameter value 'octagon' for MaskShapeMaskShapeMaskShapeMaskShapemaskShape 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_shapeGrayErosionShapeGrayErosionShapeGrayErosionShape 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_shapeGrayErosionShapeGrayErosionShapeGrayErosionShape 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

• 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_shapeGrayErosionShapeGrayErosionShapeGrayErosionShape returns 2 (H_MSG_TRUE) if all parameters are correct.

Alternatives

gray_erosiongray_erosionGrayErosionGrayErosionGrayErosion, gray_erosion_rectgray_erosion_rectGrayErosionRectGrayErosionRectGrayErosionRect

See also

gray_opening_shapegray_opening_shapeGrayOpeningShapeGrayOpeningShapeGrayOpeningShape, gray_closing_shapegray_closing_shapeGrayClosingShapeGrayClosingShapeGrayClosingShape, gray_skeletongray_skeletonGraySkeletonGraySkeletonGraySkeleton

Module

Foundation