gray_opening_shapegray_opening_shapeGrayOpeningShapeGrayOpeningShapegray_opening_shape (Operator)

Name

gray_opening_shapegray_opening_shapeGrayOpeningShapeGrayOpeningShapegray_opening_shape — Perform a gray value opening with a selected mask.

Signature

Description

gray_opening_shapegray_opening_shapeGrayOpeningShapeGrayOpeningShapeGrayOpeningShapegray_opening_shape applies a gray value opening to the input image ImageImageImageImageimageimage with the structuring element of shape MaskShapeMaskShapeMaskShapeMaskShapemaskShapemask_shape. The mask's offset values are 0 and its horizontal and vertical size is defined by MaskHeightMaskHeightMaskHeightMaskHeightmaskHeightmask_height and MaskWidthMaskWidthMaskWidthMaskWidthmaskWidthmask_width. The resulting image is returned in ImageOpeningImageOpeningImageOpeningImageOpeningimageOpeningimage_opening.

If the parameters MaskHeightMaskHeightMaskHeightMaskHeightmaskHeightmask_height or MaskWidthMaskWidthMaskWidthMaskWidthmaskWidthmask_width 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 ImageOpeningImageOpeningImageOpeningImageOpeningimageOpeningimage_opening is interpolated from the two intermediate images. Therefore, note that gray_opening_shapegray_opening_shapeGrayOpeningShapeGrayOpeningShapeGrayOpeningShapegray_opening_shape returns different results for mask sizes of, e.g., 4 and 4.0!

In case of the values 'rhombus' and 'octagon' for the MaskShapeMaskShapeMaskShapeMaskShapemaskShapemask_shape control parameter, MaskHeightMaskHeightMaskHeightMaskHeightmaskHeightmask_height and MaskWidthMaskWidthMaskWidthMaskWidthmaskWidthmask_width must be equal. The parameter value 'octagon' for MaskShapeMaskShapeMaskShapeMaskShapemaskShapemask_shape 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.

The gray value opening of an image i with a structuring element s is defined as i.e., an erosion of the image with s followed by a dilation with s (see gray_erosion_shapegray_erosion_shapeGrayErosionShapeGrayErosionShapeGrayErosionShapegray_erosion_shape and gray_dilation_shapegray_dilation_shapeGrayDilationShapeGrayDilationShapeGrayDilationShapegray_dilation_shape).

Attention

Note that gray_opening_shapegray_opening_shapeGrayOpeningShapeGrayOpeningShapeGrayOpeningShapegray_opening_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_opening_shapegray_opening_shapeGrayOpeningShapeGrayOpeningShapeGrayOpeningShapegray_opening_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

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

Alternatives

gray_openinggray_openingGrayOpeningGrayOpeningGrayOpeninggray_opening

See also

gray_dilation_shapegray_dilation_shapeGrayDilationShapeGrayDilationShapeGrayDilationShapegray_dilation_shape, gray_erosion_shapegray_erosion_shapeGrayErosionShapeGrayErosionShapeGrayErosionShapegray_erosion_shape, openingopeningOpeningOpeningOpeningopening

Module

Foundation