Calculates an Image Derivatives Using an Extended Sobel Operator

sobel calculates the first, second, third, or mixed image derivatives of an image using an extended Sobel operator.

Usage

sobel(
  image,
  dx = 1,
  dy = 1,
  k_size = 5,
  scale = 1,
  target = "new",
  in_place = NULL
)

Arguments

image

An Image object.

dx

Order of the x derivative (default: 1).

dy

Order of the y derivative (default: 1),

k_size

The half-size in pixels of the kernel (default: 5).

scale

The scale factor for the computed derivative values (default: 1).

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).

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 dimensions, number of channels, and bit depth as image, an error may be thrown.

in_place

Deprecated. Use target instead.

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, laplacian, scharr

Author

Simon Garnier, garnier@njit.edu

Examples

balloon <- image(system.file("sample_img/balloon1.png", package = "Rvision"))
balloon_sobel <- sobel(balloon)