| pnm {pixmap} | R Documentation |
Reading and writing of bitmap images in PBM (black/white), PGM (grey) and PPM (color) format.
read.pnm(file, ...)
write.pnm(object, file="Rimage.pnm", forceplain=FALSE,
type=NULL, maxval=255)
file |
name of the pnm file. |
... |
Further arguments passed to pixmap (like
bbox). |
object |
an object of class "pixmap". |
forceplain |
If TRUE, an ASCII pnm file is written.
Default is to write a binary (raw) file. |
type |
One of "pbm", "pgm" or "ppm". Default
is to use "pgm" for grey images and "ppm" for color
images. |
maxval |
The maximum color-component value, the default is a colour depth of 8 bits, i.e., the integer 255. |
read.pnm reads a pnm file and loads the image into an
object of class pixmap.
write.pnm writes an object of class pixmap to a
pnm file, the type argument controls wheter the written image
file is a black-and-white bitmap (pbm), grey (pgm) or color (ppm).
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.
read.pnm returns an object of class pixmapRGB for color
pixmaps (ppm), and an object of class pixmapGrey for pbm
and pgm.
Roger Bivand and Friedrich Leisch
x <- read.pnm(system.file("pictures/logo.ppm", package="pixmap")[1])
plot(x)
print(x)
x <- read.pnm(system.file("pictures/logo.pgm", package="pixmap")[1])
plot(x)
x <- read.pnm(system.file("pictures/logo.pbm", package="pixmap")[1])
plot(x)