ppmtosixel(1) - phpMan

Ppmtosixel User Manual(0) Ppmtosixel User Manual(0)

NAME
ppmtosixel - convert a PPM image to DEC sixel format

SYNOPSIS
ppmtosixel

[-raw]

[-margin]

[ppmfile]

DESCRIPTION
This program is part of Netpbm(1).

ppmtosixel reads a PPM image as input and 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, ppmtosixel rescales them to maxval
100. A printer control header and a color assignment table begin the SIX file. Image
data is in a compressed format by default. A printer control footer ends the image file.

OPTIONS
-raw If you specify this, 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 magnitude larger than a compressed file and prints much slower.

-margin
If you don't specify -margin, the image will start at the left margin (of the win-
dow, paper, or whatever). If you do specify -margin, 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
filename > /dev/tty0?.

LIMITATIONS
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.