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.TH ppmtofb 1 "12 November 1998" \" -*- nroff -*-
.SH NAME
ppmtofb \- display a portable pixmap on a framebuffer
.SH SYNOPSIS
.B ppmtofb
[\-h] [\-V] [\-v] [\-c] [\-w
.I delay
] [\-d
.I depth
] [\-g] [\-f
.I device
] [\-s] [\-n] [\-H] [\-x
.I cutoff
]
[\-\-help] [\-\-version] [\-\-verbose] [\-\-center] [\-\-centre]
[\-\-delay
.I delay
] [\-\-depth
.I depth
] [\-\-grayscale] [\-\-greyscale] [\-\-framebuffer
.I device
] [\-\-stdin] [\-\-no\-histogram] [\-\-no\-ham] [\-\-cutoff
.I cutoff
] [ file... ]
.SH DESCRIPTION
Reads at least one portable pixmap as input, and renders it (or them,
in sequence) to a free virtual terminal. You must specify at least
one filename or use
.B \-\-stdin
to represent standard input (for use in a pipeline).
.SH OPTIONS
.TP
.B "\-h, \-\-help"
Show a brief summary of the options permitted.
.TP
.B "\-V, \-\-version"
Display the version and copyright of
.BR ppmtofb .
.TP
.B "\-v, \-\-verbose"
Write information about each image to stderr.
.TP
.B "\-c, \-\-center, \-\-centre"
Center the image on the visible display area (if possible).
.TP
.B "\-w, \-\-delay"
Set the mininum delay between images, in seconds. (Default: 5). Note
that the time an image is displayed while another is loading is
included in this delay period (so if it takes longer than the delay
period to load the next image, the delay will be extended).
.TP
.B "\-d, \-\-depth"
Set the color depth for images. Defaults to the depth of the current mode.
.TP
.B "\-s, \-\-stdin"
Use standard input instead of reading files from the command line.
.TP
.B "\-g, \-\-grayscale, \-\-greyscale"
Render all images in grayscale. This can be significantly faster than
color display on low-color displays.
.TP
.B "\-r, \-\-random\-dither"
Use a random dithering algorithm to improve the grayscale display by
simulating a 256-grayscale display. Only effective if \-g is also
specified or the image just happens to be grayscale.
.TP
.B "\-f, \-\-framebuffer, \-\-frame\-buffer"
Specify the framebuffer device to use. This defaults to
.BR /dev/fb0 .
.TP
.B "\-n, \-\-no\-histogram"
Don't make any attempt to profile the image; instead, use the default
palette. This is much faster for Amiga HAM displays (and only affects
HAM), but the resulting output is somewhat lower in quality.
.TP
.B "\-H, \-\-no\-ham"
Don't use HAM modes, even if available.
.TP
.B "\-x, \-\-cutoff"
Ignore colors that have fewer than N pixels in the image of that color
when determining the palette (HAM only). Defaults to 0.01% of the
pixels in the image.
.SH ENVIRONMENT
.TP
.B FRAMEBUFFER
The framebuffer device to use. (Default: /dev/fb0.)
.SH EXAMPLES
.TP
.B "ppmtofb linux-logo.ppm"
Display the PPM file
.B linux-logo.ppm
and exit, using the default options.
.TP
.B "djpeg humberto-flores.jpg | ppmtofb \-\-stdin"
Display the JPEG file
.B humberto-flores.jpg
and exit, using the default options (via the \-\-stdin feature of
ppmtofb).
.SH BUGS/LIMITATIONS
Displaying images with more than 256 colors only works on Amigas with
the AGA chipset (and works somewhat on Amigas with other chipsets), or
on DIRECTCOLOR/TRUECOLOR visuals. You can work around this limitation
using ppmquant or ppmdither. The
.B \-\-grayscale
and
.B \-\-random\-dither
options will also be useful in this regard. See
.B fbview
for an automated solution to this problem.
PSEUDOCOLOR only works with up to 256 colors. However, no existing
framebuffer device supports PSEUDOCOLOR with more than 256 colors.
The DIRECTCOLOR and TRUECOLOR implementation expects each pixel to
start and end at a byte-boundary. This means that modes like NeXT
12-bit truecolor (4 bits per gun) are not supported. However, this
limitation does not affect any existing framebuffer device.
Depths greater than 32 bpp are not supported. Anyone who needs more
than 32 bpp has significantly better vision than I do.
Static-color modes other than grayscale (such as macfb) are completely
unsupported. Supporting them properly would require incorporating
quantization and dithering routines.
Supporting palette-based image formats (like PNG and GIF) directly
would increase speed on non-truecolor/directcolor systems.
Various dialects of the English language permit too many spellings of
useful parameters.
The program probably keeps the root UID too long.
.SH "SEE ALSO"
ppmdither(1), ppmquant(1), fbview(1), fb.modes(5), ppm(5), fbset(8),
/usr/src/linux/Documentation/fb/framebuffer.txt
.SH AUTHORS
Geert Uytterhoeven <Geert.Uytterhoeven@cs.kuleuven.ac.be> and
Chris Lawrence <lawrencc@debian.org>
HAM8 rendering code originally written by Guenther Roehrich
<Guenther@studbox.uni-stuttgart.de> (as part of the AmigaOS jpegAGA
package), although it has been more-or-less rewritten multiple times
by Chris.
The VGA16 rendering code was unabashedly lifted from the
.B bogl
library, by Ben Pfaff <pfaffben@debian.org>.
Copyright (C) 1996 Geert Uytterhoeven and (C) 1996-2000 Chris Lawrence.
This software may be redistributed under the terms of the GNU General
Public License, version 2 (or, at your option, a later version).
Portions of the HAM code were taken from ppmtoilbm, which is copyright
(C) 1989 by Jef Poskanzer and modified by Ingo Wilken. Those portions
are licensed as follows:
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted, provided
that the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation. This software is provided "as is" without express or
implied warranty.
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