bin.erosion {espadon}

Binary volume erosion

Description

The bin.erosion function decreases a "volume" class object, of "binary" modality, by means of convolution with a sphere. Erosion is useful for :

• removing volumes that are smaller than the radius,

• eliminating narrow capes,

• enlarging channels,

• turning peninsulas into islands.

Usage

bin.erosion(vol, radius = 10, alias = "", description = NULL)

Arguments

vol

"volume" class object, of "binary" modality

radius

Positive number, in millimeters. By default, radius = 10.

alias

Character string, $object.alias of the created object.

description

Character string, describing the created object. If description = NULL (default value), it will be set to paste (vol$object.alias, "erosion r =", radius).

Value

Returns a "volume" class object of "binary" modality (see espadon.class for class definitions), with the same grid as vol, in which the selected volume has been reduced by the radius.

Note

Erosion can be time consuming, try to reduce the binary volume to the strict minimum, before any operations.

See Also

bin.dilation, bin.opening, bin.closing, add.margin, nesting.cube.

Examples

# loading of toy-patient objects (decrease dxyz for better result)
step <- 4
patient <- toy.load.patient (modality = "mr", roi.name = "", 
                             dxyz = rep (step, 3))
MR <- patient$mr[[1]]

# generation of a binary volume
b <- bin.from.vol(MR, min = 15,max = 30)

b.erosion <- bin.erosion (b, radius = step)
display.plane (bottom = MR, top = b, main = "Before erosion", 
               view.coord = -20, interpolate = FALSE)
display.plane (bottom = MR, top = b.erosion, main = "After erosion", 
               view.coord = -20, interpolate = FALSE)