| edges {adimpro} | R Documentation |
Image Processing
Description
Edge detection using Laplacian, Sobel, or Robert Cross filter.
Usage
edges(img, type = "Laplacian", ltype=1, abs=FALSE)
Arguments
img |
an object of class "adimpro". |
type |
type of edges detection filter. "Laplacian" (default), "Sobel" , or "Robertcross". |
ltype |
type of laplacian filter. 1,2,3, or 4 |
abs |
take absolute values of results. This has only an effect for
|
Details
This function applies the Laplacian, Sobel, or Robert Cross filter to
the input image img. The filter is applied to each color channel separately. ltype determines
the different matrices for Laplacian filter used in the
literature. ltype == 1 will use:
conv <- matrix(c(-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,
-1,-1,24,-1,-1,
-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1),5,5)
ltype == 2 will use:
conv <- matrix(c(0,-1,0,-1,4,-1,0,-1,0), 3, 3)
ltype == 3 will use:
conv <- matrix(c(-1,-1,-1,-1,8,-1,-1,-1,-1), 3, 3)
ltype == 4 (default) will use:
conv <- matrix(c(1,-2,1,-2,4,-2,1,-2,1), 3, 3)
Value
Array containing the values for the edge detector in each pixel and color channel.
Author(s)
Karsten Tabelow tabelow@wias-berlin.de and Joerg Polzehl polzehl@wias-berlin.de
References
Gonzalez, R.C., and Woods, R.E. (2002). Digital Image Processing. Prentice Hall.
Examples
## Not run: demo(manipulate)
## Not run: demo(awspimage)