phpman > man > ppmtosixel(1)

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⚡ TLDR: ppmtosixel (tldr-pages)

Convert a PPM image to DEC sixel format.

Convert a PPM image to DEC sixel format
ppmtosixel {{path/to/file.ppm}} > {{path/to/file.sixel}}
Produce an uncompressed SIXEL file that is much slower to print
ppmtosixel {{-r|-raw}} {{path/to/file.ppm}} > {{path/to/file.sixel}}
Add a left margin of 1.5 inches
ppmtosixel {{-m|-margin}} {{path/to/file.ppm}} > {{path/to/file.sixel}}
Encode control codes in a more portable (although less space-efficient) way
ppmtosixel -7bit {{path/to/file.ppm}} > {{path/to/file.sixel}}

ppmtosixel(1) General Commands Manual ppmtosixel(1)

NAME
ppmtosixel - convert a portable pixmap into DEC sixel format

SYNOPSIS
ppmtosixel [-raw] [-margin] [ppmfile]

DESCRIPTION
Reads a portable pixmap as input. Produces sixel commands (SIX) as output. The output is
formatted for color printing, e.g. for a DEC LJ250 color inkjet printer.

If RGB values from the PPM file do not have maxval=100, the RGB values are rescaled. A
printer control header and a color assignment table begin the SIX file. Image data is writ‐
ten in a compressed format by default. A printer control footer ends the image file.

OPTIONS
-raw If specified, each pixel will be explicitly described in the image file. If -raw is
not specified, output will default to compressed format in which identical adjacent
pixels are replaced by "repeat pixel" commands. A raw file is often an order of mag‐
nitude larger than a compressed file and prints much slower.

-margin
If -margin is not specified, the image will be start at the left margin (of the win‐
dow, paper, or whatever). If -margin is specified, a 1.5 inch left margin will offset
the image.

PRINTING
Generally, sixel files must reach the printer unfiltered. Use the lpr -x option or cat file‐
name > /dev/tty0?.

BUGS
Upon rescaling, truncation of the least significant bits of RGB values may result in poor
color conversion. If the original PPM maxval was greater than 100, rescaling also reduces
the image depth. While the actual RGB values from the ppm file are more or less retained,
the color palette of the LJ250 may not match the colors on your screen. This seems to be a
printer limitation.