.\" $Id: fiasco_d_options_new.3,v 1.1 2000/10/28 17:35:12 hafner Exp $
.TH fiasco 3 "April, 2000" "FIASCO" "Fractal Image And Sequence COdec"

.SH NAME
.B  fiasco_d_options_new, fiasco_d_options_set_magnification,
.B fiasco_d_options_delete, fiasco_d_options_set_smoothing
.B fiasco_d_options_set_4_2_0_format
\- define additional options of FIASCO decoder 

.SH SYNOPSIS
.B #include <fiasco.h>
.sp
.BI "fiasco_d_options_t *"
.fi
.BI "fiasco_d_options_new"
.fi
.BI "   (void);"
.sp
.BI "void"
.fi
.BI "fiasco_d_options_delete"
.fi
.BI "   (fiasco_d_options_t * "options );
.sp
.BI "int"
.fi
.BI "fiasco_d_options_set_4_2_0_format"
.fi
.BI "   (fiasco_d_options_t * "options ,
.fi
.BI "    int "format );
.sp
.BI "int"
.fi
.BI "fiasco_d_options_set_magnification"
.fi
.BI "   (fiasco_d_options_t * "options ,
.fi
.BI "    int "level );
.sp
.BI "int"
.fi
.BI "fiasco_d_options_set_smoothing"
.fi
.BI "   (fiasco_d_options_t * "options ,
.fi
.BI "    unsigned "smoothing );
.fi

.SH DESCRIPTION
The \fBfiasco_d_options_new()\fP function allocates and initializes a
FIASCO options object which is used to control additional
decompression parameters.

Conversely, the function \fBfiasco_d_options_delete()\fP discards the
given FIASCO decoder options object.

Several member functions are available to modify the default behavior
of the FIASCO decoder.

\fBfiasco_d_options_set_smoothing()\fP sets the
\fIsmoothing\fP-percentage along partitioning borders when the images
are regenerated; default is 70.

\fBfiasco_d_options_set_magnification()\fP sets the \fImagnification\fP
of the regenerated image; default is 0, i.e., the image geometry is
not changed.

\fBfiasco_d_options_set_4_2_0_format()\fP defines whether the decoder
should use the default 4:4:4 format or the 4:2:0 format. The latter
one significantly reduces the decoding time at the cost of some
additional blocking artefacts.

.SH ARGUMENTS
.TP
options
This object encapsulates various decoding parameters.  

.TP
smoothing
This percentage (range is 0 - i.e., no smoothing - to 100) defines how
much the regenerated image is smoothed along the partitioning borders.

.TP
level
This value gives the magnification of the decoded image with respect
to the original size. Positive values increase and negative values
decrease the width and height of the image by a factor of
2^abs(\fIlevel\fP).

.TP
format
If \fIformat\fP is 0 then the 4:4:4 color image format is used, i.e.,
the chroma channel are of the same size as the luminance. Otherwise,
the 4:2:0 format is used. Then, width and height of each chroma
channel is only one half of the width and height of the luminance.

.SH RETURN VALUES
The function \fBfiasco_d_options_new()\fP returns a pointer to the
newly allocated decoder option object. If an error has been catched, a
NULL pointer is returned.

All set functions return 1 on success and 0 if an error has been
catched.  

In case of an error, use the function fiasco_get_error_message(3) to
get a string with the last error message of FIASCO.

.SH "SEE ALSO"
.br
.BR fiasco_decoder "(3), " fiasco_coder (3)

Ullrich Hafner, Juergen Albert, Stefan Frank, and Michael Unger.
\fBWeighted Finite Automata for Video Compression\fP, IEEE Journal on
Selected Areas In Communications, January 1998
.br
Ullrich Hafner. \fBLow Bit-Rate Image and Video Coding with Weighted
Finite Automata\fP, Ph.D. thesis, Mensch & Buch Verlag, ISBN
3-89820-002-7, October 1999.

.SH AUTHOR
Ullrich Hafner <hafner@bigfoot.de>