morphology {adehabitat} | R Documentation

## Morphology: Erosion or Dilatation of Features on a Raster Map

### Description

`morphology` performs morphological operations on images of class `asc`.

### Usage

    morphology(x, operation = c("erode", "dilate"), nt = 5)

### Arguments

`x` | a matrix of class `asc`
`operation` | a character string indicating the operation to be processed: either `"erode"` or `"dilate"`
`nt` | the number of times that the operation should be processed

### Value

Returns a matrix of class `asc`, containing 1 when the pixel belong to one feature of the image and `NA` otherwise (see examples).

### Author(s)

Clément Calenge calenge@biomserv.univ-lyon1.fr

### See Also

`as.asc` for further information on objects of class `asc`

### Examples

    data(puechabon)
    a <- getkasc(puechabon$kasc,"Elevation")

    ## dilatation
    toto1 <- morphology(a, operation = "dilate", nt = 1)
    toto2 <- morphology(a, operation = "dilate", nt = 2)
    toto3 <- morphology(a, operation = "dilate", nt = 3)
    toto5 <- morphology(a, operation = "dilate", nt = 5)
    image(toto5, col = "red")
    image(toto3, add = TRUE, col = "orange")
    image(toto2, add = TRUE, col = "yellow")
    image(toto1, add = TRUE, col = "green")
    image(a, add = TRUE)

    ## erosion
    image(a, col = 1)
    for (i in 1:19) {
      toto <- morphology(a, operation = "erode", nt = i)
      image(toto, add = TRUE, col = palette()[(i+1)%%8])
    }

[Package adehabitat version 1.3 Index]