im {spatstat} | R Documentation |
Creates an object of
class "im"
representing a two-dimensional pixel image.
im(mat, xcol=seq(ncol(mat)), yrow=seq(nrow(mat)), lev=levels(mat))
mat |
matrix or vector containing the pixel values of the image. |
xcol |
vector of x coordinates for the pixels |
yrow |
vector of y coordinates for the pixels |
lev |
possible factor levels, if mat should be interpreted
as a factor.
|
This function creates an object of class "im"
representing
a two-dimensional pixel image. See im.object
for details of this class.
If mat
is not a matrix, it will first be converted into
a matrix with nrow(mat) = length(yrow)
and
ncol(mat) = length(xcol)
.
Note that the row index of the matrix mat
corresponds
to increasing y coordinate, while the column index of mat
corresponds to increasing x coordinate. Thus
xrow
has one entry for each row of mat
and ycol
has one entry for each column of mat
. A correct
display of the image would be obtained by transposing, e.g.
image.default(xcol, yrow, t(mat))
, if you wanted to do it by hand.
The internal representation of images is likely to change in the next release of this package.
Adrian Baddeley adrian@maths.uwa.edu.au http://www.maths.uwa.edu.au/~adrian/ and Rolf Turner rolf@math.unb.ca http://www.math.unb.ca/~rolf
whitenoise <- im(matrix(rnorm(10000), 100, 100)) image(whitenoise)