Computer Science
pnmtoddif(1) pnmtoddif(1)
Name
pnmtoddif - Convert a portable anymap to DDIF format
Syntax
pnmtoddif pnmtoddif [-resolution x y] [pnmfile [ddiffile]]
OPTIONS
resolution x y The horizontal and vertical resolution of
the output image in dots per inch. Defaults
to 78 dpi.
pnmfile The filename for the image file in pnm for-
mat. If this argument is omitted, input is
read from stdin.
ddiffile The filename for the image file to be cre-
ated in DDIF format. If this argument is
omitted, the ddiffile is written to stan-
dard output. It can only specified if a
pnmfile is also specified.
DESCRIPTION
pnmtoddif takes a portable anymap from standard input and
converts it into a DDIF image file on standard output or
the specified DDIF file.
pbm format (bitmap) data is written as 1 bit DDIF, pgm
format data (greyscale) as 8 bit greyscale DDIF, and ppm
format data is written as 8,8,8 bit color DDIF. All DDIF
image files are written as uncompressed. The data plane
organization is interleaved by pixel.
In addition to the number of pixels in the width and
height dimension, DDIF images also carry information about
the size that the image should have, that is, the physical
space that a pixel occupies. PBMPLUS images do not carry
this information, hence it has to be externally supplied.
The default of 78 dpi has the beneficial property of not
causing a resize on most Digital Equipment Corporation
color monitors.
AUTHOR
Burkhard Neidecker-Lutz
Digital Equipment Corporation, CEC Karlsruhe
neideck@nestvx.enet.dec.com
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