im.object {spatstat}R Documentation

Class of Images

Description

A class "im" to represent a two-dimensional pixel image.

Details

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.

Image objects may be displayed using the methods plot.im, image.im, persp.im and contour.im. Values of an image may be looked-up using lookup.im or using the subset operator [.im. Calculations involving one or more images (for example, subtracting one image from another) can often be done easily using eval.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.

Warnings

The internal representation of images is likely to change in the next release of this package.

Author(s)

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

See Also

im, Kmeasure, setcov, plot.im, eval.im, lookup.im


[Package spatstat version 1.6-12 Index]