pnmtofiasco - Convert PNM file to FIASCO compressed file
SYNOPSIS
pnmtofiasco
[option]...
[filename]...
DESCRIPTION
pnmtofiasco
compresses the named pbm, pgm, or ppm image files, or Standard Input
if no file is named, and produces a FIASCO file on Standard Output.
OPTIONS
All option names may be abbreviated; for example, --optimize may be
written --optim or --opt. For most options a one letter short option
is provided. Mandatory or optional arguments to long options are
mandatory or optional for short options, too. Both short and long
options are case sensitive.
The basic options are:
-iname, --input-name=name
Compress the named images, not Standard Input.
If
name
is
-,
read Standard Input.
name
has to be either an image filename or a template of the form:
prefix[start-end{+,-}step]suffix
Templates are useful when compressing video streams: e.g., if you specify
the template
img0[12-01-2].pgm,
then
pnmtofiasco
compresses the images img012.pgm, img010.pgm, ..., img002.pgm.
If
name
is a relative path,
pnmtofiasco
searches for the image files in the current directory and in the
(colon-separated) list of directories given by the environment
variable
FIASCO_IMAGES.
-ooutput-file, --output-name=name
Write FIASCO output to the named file, not to Standard Output.
If
name
is a relative path and the environment variable
FIASCO_DATA
is a (colon-separated) list of directories, then
pnmtofiasco
writes the output file to the first (writable) directory of this
list. Otherwise,
pnmtofiasco
write it to the current directory.
-qN, --quality=N
Set quality of compression to
N.
Quality is 1 (worst) to 100 (best); default is 20.
-v, --version
Print
pnmtofiasco
version number, then exit.
-VN, --verbose N
Set level of verbosity to
N.
Level is 0 (no output at all), 1 (show progress meter), or 2 (show
detailed compression statistics); default is 1.
-BN, --progress-meter N
Set type of progress-meter to
N.
The following types are available; default is 1:
0:
no progress meter
1:
RPM style progress bar using 50 hash marks
2:
percentage meter
-fname, --config=name
Load parameter file
name
to initialize the options of
pnmtofiasco.
See file
system.fiascorc
for an example of the syntax. Options of
pnmtofiasco
are set by any of the following methods (in the specified order):
1) Global ressource file
/etc/system.fiascorc
2) $HOME/.fiascorc
3) command line
4) --config=name
-h, --info
Print brief help, then exit.
-H
, --help
Print detailed help, then exit.
The options for advanced users are:
-b
name, --basis-name=name
Preload compression basis name into FIASCO. The basis name
provides the initial compression dictionary. Either use one of the
files "small.fco", "medium.fco", or "large.fco" that come with
pnmtofiasco
or create a new ASCII basis file.
-zN, --optimize=N Set optimization level to
N. Level is 0 (fastes) to 3 (slowest); default is 1. Be warned,
the encoding time dramatically increased when N=2 or
N=3 while the compression performance only slightly
improves.
-P, --prediction
Use additional predictive coding. If this optimization is enabled then
the image is compressed in two steps. In the first step, a coarse
approximation of the image is computed using large unichrome
blocks. Finally, the delta image is computed and the prediction error
is approximated using the standard FIASCO algorithm.
-D
N, --dictionary-size=N
Set size of dictionary that is used when coding the luminance
band to N; default is 10000, i.e., the dictionary is not
restricted.
-CN, --chroma-dictionary=N
Set size of dictionary that is used when coding chroma bands to
N; default is 40.
-QN, --chroma-qfactor=N
Reduce the quality of chroma band compression N-times with
respect to the user defined quality q of the luminance
band compression (--quality=q); default is 2.
-tN, --tiling-exponent=N
Subdivide the image into 2^N tiles prior coding; default is 4,
i.e. the image is subdivided into 16 tiles. The processing order of
the individual tiles is defined by the option
--tiling-method=name.
-Tname, --tiling-method=name
Order the individual image tiles (the image is subdivided into; see
option --tiling-exponent=N) by method name; default
is "desc-variance".
desc-variance: Tiles with small variances are processed first.
asc-variance: Tiles with large variances are processed first.
desc-spiral: Tiles are process in spiral order starting in the
middle.
asc-spiral: Tiles are process in spiral order starting at the
border.
--rpf-mantissa=N
Use N mantissa bits for quantized coefficients.
--dc-rpf-mantissa=N
Use N mantissa bits for quantized DC coefficients.
--rpf-range=N
Coefficients outside the quantization interval [-N,+N] are
set to zero.
--dc-rpf-range=N
DC coefficients outside the quantization interval [-N,+N] are
set to zero.
Additional options for video compression are:
-sN, --smooth=N
Smooth decompressed reference frames along the partitioning borders by
the given amount N. N is 0 (no smoothing) to 100; default
is 70. This factor is stored in the FIASCO file.
-mN, --min-level=N
Start prediction (motion compensated prediction or additional prediction) on
block level N; default is level 6. I.e., motion compensation is
applied to all image blocks of at least 8x8 pixels (binary tree level
N=6), 16x8 (N=7), 16x16 (N=8), etc.
-MN, --max-level=N
Stop prediction (motion compensated prediction or additional prediction) on
block level N; default is level 10. I.e., motion compensation is
applied to all image blocks of at most 16x16 pixels (N=8),
32x16 (N=9), 32x32 (N=10), etc.
-2, --half-pixel
Use half pixel precise motion compensation.
-F
N, --fps=N
Set number of frames per second to N. This value is stored in
the FIASCO output file and is used in the decoder dfiasco(1) to control the
framerate.
-ptype, --pattern=type
Defines the type of inter frame compression which should be applied to
individual frames of a video stream. type is a sequence of
characters; default is "IPPPPPPPPP". Element N defines the type
of predicting which should be used for frame N; the frame type
pattern is periodically extended. Valid characters are:
I: intra frame, i.e., no motion compensated prediction is used at
all.
P: predicted frame, i.e., a previously encoded frame is used for
prediction (forward prediction).
B: bidirectional predicted frame, i.e., not only a previously
shown frame but also a frame of the future is used for prediction
(forward, backward or interpolated prediction).
--cross-B-search
Instead of using exhaustive search the "Cross-B-Search" algorithm
is used to find the best interpolated prediction of B-frames.
--B-as-past-ref
Also use previously encoded B-frames when prediction the current
frame. If this option is not set, only I- and P-frames are used to
predict the current frame.
EXAMPLES
pnmtofiasco < foo.ppm >foo.wfa
Compress the still image "foo.ppm" to the FIASCO file "foo.wfa" using
the default options.
Compress the video frames "foo0*.ppm" to the FIASCO file "video.wfa" using
half pixel precise motion compensation at a frame rate of 15 frames
per second. Intra frame 1 is used to predict P-frame 4, frames 1 and 4
are used to predict B-frames 2 and 3, and so on. Frame 10 is again an
intra-frame.
FILES
/etc/system.fiascorc
The systemwide initialization file.
$HOME/.fiascorc
The personal initialization file.
ENVIRONMENT
FIASCO_IMAGES
Search path for image files. Default is "./".
FIASCO_DATA
Search and save path for FIASCO files. Default is "./".
Ullrich Hafner, Juergen Albert, Stefan Frank, and Michael Unger.
Weighted Finite Automata for Video Compression, IEEE Journal on
Selected Areas In Communications, January 1998
Ullrich Hafner. Low Bit-Rate Image and Video Coding with Weighted
Finite Automata, Ph.D. thesis, Mensch & Buch Verlag, ISBN
3-89820-002-7, October 1999.