pnmtoddif(1) - man - phpman

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⚡ TLDR: pnmtoddif (tldr-pages)

Convert a PNM image to a DDIF image file.

Convert a PNM image to a DDIF image file
pnmtoddif {{path/to/image.pnm}} > {{path/to/image.ddif}}
Explicitly specify the horizontal and vertical resolution of the output image
pnmtoddif {{-r|-resolution}} {{horizontal_dpi}} {{vertical_dpi}} {{path/to/image.pnm}} > {{path/to/image.ddif}}

pnmtoddif(1) General Commands Manual 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 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 argu‐
ment is omitted, the ddiffile is written to standard output. It can only spec‐
ified 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 AT nestvx.com

pnmtoddif(1)