# rescale.im

##### Convert Pixel Image to Another Unit of Length

Converts a pixel image to another unit of length.

##### Usage

```
# S3 method for im
rescale(X, s, unitname)
```

##### Arguments

- X
Pixel image (object of class

`"im"`

).- s
Conversion factor: the new units are

`s`

times the old units.- unitname
Optional. New name for the unit of length. See

`unitname`

.

##### Details

This is a method for the generic function `rescale`

.

The spatial coordinates of the pixels in `X`

will be re-expressed
in terms of a new unit of length that is `s`

times the current
unit of length given in `X`

.
(Thus, the coordinate values are *divided* by `s`

,
while the unit value is multiplied by `s`

).

If `s`

is missing, then the coordinates will be re-expressed
in ‘native’ units; for example if the current unit is
equal to 0.1 metres, then the coordinates will be re-expressed in metres.

The result is a pixel image representing the *same* data
but re-expressed in a different unit.

Pixel values are unchanged. This may not be what you intended!

##### Value

Another pixel image (of class `"im"`

),
containing the same pixel values, but with pixel coordinates
expressed in the new units.

##### See Also

##### Examples

```
# NOT RUN {
# Bramble Canes data: 1 unit = 9 metres
data(bramblecanes)
# distance transform
Z <- distmap(bramblecanes)
# convert to metres
# first alter the pixel values
Zm <- eval.im(9 * Z)
# now rescale the pixel coordinates
Z <- rescale(Zm, 1/9)
# or equivalently
Z <- rescale(Zm)
# }
```

*Documentation reproduced from package spatstat, version 1.63-0, License: GPL (>= 2)*