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 format. If this
argument is omitted, input is read from stdin.
- ddiffile
- The filename for the image file to be created in DDIF
format. If this argument is omitted, the ddiffile is written to standard
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