

   PPoorrttaabbllee AAnnyymmaapp IImmaaggeess

        read.pnm(file)
        plot(pnmobj, xlab="", ylab="", axes=FALSE, ...)
        write.pgm(pnmobj, file="Rimage.pgm", forceplain=FALSE)

   AArrgguummeennttss::

     pnmobj: an object of class `pnm'

       file: name of the pnm file

   forceplain: If `TRUE', an ASCII pgm file is written. Default
             is to write a binary (raw) pgm file.

   DDeessccrriippttiioonn::

        `read.pnm' reads a pnm file and loads the image into an
        object of class `pnm', which is basically a matrix
        (pbm, pgm) or a 3-dimensional arry with 3 matrices for
        red, green and blue.

        `write.pgm' writes an object of class `pnm' to a pgm
        file. Generalizations for writing pbm and ppm files are
        yet to be written.

        `plot.pnm' plots a pnm object using the command
        `image'. The only difference is that the element
        `[1,1]' of `pnmobj' is plotted as the upper left corner
        (plain `image' would plot `[1,1]' as the lower left
        corner.

   VVaalluuee::

        `read.pnm' returns an object of class `pnm'. The maxi-
        mum value (of either grey or the red/green/blue chan-
        nels) is stored as attribute `"maxval"'). The type
        (pbm, pgm or pnm) is stred as attribute `"type"').

   AAuutthhoorr((ss))::

        Friedrich Leisch

   SSeeee AAllssoo::

        `image'

