MultiScaleMorphologicalGradient

Morphological edge detector

SYNOPSIS

#include "dip_morphology.h"

dip_Error dip_MultiScaleMorphologicalGradient ( in, out, se, boundary, upperSize, lowerSize, shape )

DATA TYPES

integer, float

FUNCTION

This function computes the average morphological gradient over a range of scales bounded by upperSize and lowerSize. The morphological gradient is computed as the difference of the dilation and erosion of the input image at a particular scale, eroded by an erosion of one size smaller. At the lowest scale, the size of the structuring element is 2 * upperSize + 1.

The rectangular, elliptic and diamond structuring elements are "flat", i.e. these structuring elements have a constant value. For these structuring elements, param determines the sizes of the structuring elements.

When shape is DIP_FLT_SHAPE_DISCRETE_LINE or DIP_FLT_SHAPE_INTERPOLATED_LINE, the structuring element is a line. param->array[0] determines the length, param->array[1] the angle. This is currently only supported for 2D images. Interpolated lines use interpolation to obtain a more accurate result, but loose the strict increasingness and extensivity (these properties are satisfied only by approximation).

When shape is set to DIP_FLT_SHAPE_PARABOLIC, params specifies the curvature of the parabola.

When shape is set to DIP_FLT_SHAPE_STRUCTURING_ELEMENT, se is used as structuring element. It can be either a binary or a grey-value image. Its origin is the center, or one pixel to the left of the center if the size is even.

If shape is not equal to DIP_FLT_SHAPE_STRUCTURING_ELEMENT, se can be set to zero. When shape is set to DIP_FLT_SHAPE_STRUCTURING_ELEMENT, param is ignored, and can be set to zero.

ARGUMENTS

Data type	Name	Description
`dip_Image`	`in`	Input
`dip_Image`	`out`	Output
`dip_Image`	`se`	Custom structuring element
`dip_BoundaryArray`	`boundary`	Boundary conditions
`dip_int`	`upperSize`	Upper size of structuring element
`dip_int`	`lowerSize`	Lower size of structuring element
`dip_FilterShape`	`shape`	Structuring element

The enumerator dip_FilterShape contains the following constants:

Name	Description
`DIP_FLT_SHAPE_DEFAULT`	Default filter window, same as `DIP_FLT_SHAPE_RECTANGULAR`
`DIP_FLT_SHAPE_RECTANGULAR`	Rectangular filter window, can be even in size
`DIP_FLT_SHAPE_ELLIPTIC`	Elliptic filter window, always odd in size
`DIP_FLT_SHAPE_DIAMOND`	Diamond-shaped filter window, always odd in size
`DIP_FLT_SHAPE_PARABOLIC`	Parabolic filter window (morphology only)
`DIP_FLT_SHAPE_DISCRETE_LINE`	Rotated line structuring element (morphology only)
`DIP_FLT_SHAPE_INTERPOLATED_LINE`	Rotated line structuring element, through interpolation (morphology only)
`DIP_FLT_SHAPE_PERIODIC_LINE`	(not implemented)
`DIP_FLT_SHAPE_STRUCTURING_ELEMENT`	Use `se` as filter window, can be any size

LITERATURE