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_shapeGrayOpeningShapeGrayOpeningShapegray_opening_shape applies a gray value opening to the input image ImageImageImageimageimage with the structuring element of shape MaskShapeMaskShapeMaskShapemaskShapemask_shape. The mask's offset values are 0 and its horizontal and vertical size is defined by MaskHeightMaskHeightMaskHeightmaskHeightmask_height and MaskWidthMaskWidthMaskWidthmaskWidthmask_width. The resulting image is returned in ImageOpeningImageOpeningImageOpeningimageOpeningimage_opening.

If the parameters MaskHeightMaskHeightMaskHeightmaskHeightmask_height or MaskWidthMaskWidthMaskWidthmaskWidthmask_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 ImageImageImageimageimage is transformed with both the next larger and the next smaller odd mask size, and the output image ImageOpeningImageOpeningImageOpeningimageOpeningimage_opening is interpolated from the two intermediate images. Therefore, note that gray_opening_shapegray_opening_shapeGrayOpeningShapeGrayOpeningShapegray_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 MaskShapeMaskShapeMaskShapemaskShapemask_shape control parameter, MaskHeightMaskHeightMaskHeightmaskHeightmask_height and MaskWidthMaskWidthMaskWidthmaskWidthmask_width must be equal. The parameter value 'octagon' for MaskShapeMaskShapeMaskShapemaskShapemask_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_shapeGrayErosionShapeGrayErosionShapegray_erosion_shape and gray_dilation_shapegray_dilation_shapeGrayDilationShapeGrayDilationShapegray_dilation_shape).

Attention

Note that gray_opening_shapegray_opening_shapeGrayOpeningShapeGrayOpeningShapegray_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_shapeGrayOpeningShapeGrayOpeningShapegray_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_shapeGrayOpeningShapeGrayOpeningShapegray_opening_shape returns 2 ( H_MSG_TRUE) if all parameters are correct.

Alternatives

gray_openinggray_openingGrayOpeningGrayOpeninggray_opening

See also

gray_dilation_shapegray_dilation_shapeGrayDilationShapeGrayDilationShapegray_dilation_shape, gray_erosion_shapegray_erosion_shapeGrayErosionShapeGrayErosionShapegray_erosion_shape, openingopeningOpeningOpeningopening

Module

Foundation