```
opening(w, r, ...)
## S3 method for class 'owin':
opening(w, r, \dots, polygonal=NULL)
## S3 method for class 'ppp':
opening(w, r, \dots)
## S3 method for class 'psp':
opening(w, r, \dots)
```

w

A window (object of class

`"owin"`

or a line segment pattern (object of class `"psp"`

)
or a point pattern (object of class `"ppp"`

).r

positive number: the radius of the opening.

...

extra arguments passed to

`as.mask`

controlling the pixel resolution, if a pixel approximation is usedpolygonal

Logical flag indicating whether to compute a polygonal
approximation to the erosion (

`polygonal=TRUE`

) or
a pixel grid approximation (`polygonal=FALSE`

).- If
`r > 0`

, an object of class`"owin"`

representing the opened region. If`r=0`

, the result is identical to`w`

.

`W`

.For a small radius $r$, the opening operation has the effect of smoothing out irregularities in the boundary of $W$. For larger radii, the opening operation removes promontories in the boundary. For very large radii, the opened set is empty.

`closing`

for the opposite operation. `dilation`

, `erosion`

for the basic
operations.
`owin`

,
`as.owin`

for information about windows.

```
data(letterR)
v <- opening(letterR, 0.3, dimyx=256)
plot(v, main="opening")
plot(letterR, add=TRUE)
```

Run the code above in your browser using DataCamp Workspace