Section: User Commands (1)Index
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pnmtoddif - Convert a portable anymap to DDIF format
pnmtoddif [-resolution x y] [pnmfile [ddiffile]]
- resolution x y
The horizontal and vertical resolution of the output
image in dots per inch. Defaults to 78 dpi.
The filename for the image file in pnm format. If this
argument is omitted, input is read from stdin.
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.
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.
Digital Equipment Corporation, CEC Karlsruhe