im.object {spatstat} | R Documentation |
A class "im"
to represent a two-dimensional pixel image.
An object of this class represents a two-dimensional pixel image. It specifies
If X
is an object of type im
,
it contains the following elements:
v | matrix of values |
dim | dimensions of matrix v |
xrange | range of x coordinates of image window |
yrange | range of y coordinates of image window |
xstep | width of one pixel |
ystep | height of one pixel |
xcol | vector of x coordinates of centres of pixels |
yrow | vector of y coordinates of centres of pixels |
Users are strongly advised not to manipulate these entries directly.
Objects of class "im"
may be created by the function
im
. They are also returned by the functions
Kmeasure
and
setcov
.
They may be displayed using the methods
image.im
, persp.im
and contour.im
.
Values of an image may be looked-up using
lookup.im
.
Note that the row index of the matrix v
corresponds
to increasing y coordinate, while the column index of m
corresponds to increasing x coordinate. Thus a correct
display of the image would be obtained by transposing, e.g.
image.default(xcol, yrow, t(im))
, 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