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Add Border to Image

Source: R/ImageClass.R
border.Rd

border adds a border to an image.

Usage

border(
  image,
  top,
  bottom = top,
  left = top,
  right = top,
  border_type = "constant",
  border_color = "black",
  target = "new"
)

Arguments

image

An Image object.

top, bottom, left, right

The width in pixels of the border on each side of the image. By default, bottom, left and right are set to the same value as top.

border_type

A character string indicating the extrapolation method to use when filling empty pixels created during the transformation. It can be any of the following:

"constant" (the default):

iiiiii|abcdefgh|iiiiii with i specified by border_value.

"replicate":

aaaaaa|abcdefgh|hhhhhh.

"reflect":

fedcba|abcdefgh|hgfedc.

"wrap":

cdefgh|abcdefgh|abcdef.

"reflect_101":

gfedcb|abcdefgh|gfedcb.

"transparent":

uvwxyz|abcdefgh|ijklmn.

border_color

A value or vector of any kind of R color specification compatible with col2bgr representing the color of the border (default: "black").

target

The location where the results should be stored. It can take 3 values:

"new":

a new Image object is created and the results are stored inside (the default).

"self":

the results are stored back into image (faster but destructive). image will be resized accordingly.

An Image object:

the results are stored in another existing Image object. This is fast and will not replace the content of image but will replace that of target. Note that if target does not have the same number of channels and bit depth as image, an error will be thrown. If target does not have the appropriate dimensions, it will be resized accordingly.

Value

If target="new", the function returns an Image object. If target="self", the function returns nothing and modifies image in place. If target is an Image object, the function returns nothing and modifies that Image object in place.

See also

Image

Author

Simon Garnier, garnier@njit.edu

Examples

balloon <- image(system.file("sample_img/balloon1.png", package = "Rvision"))
balloon_border <- border(balloon, 10)