NAME¶
compface, uncompface - compress and expand 48x48x1 face image files
SYNOPSIS¶
compface [
infile [
outfile ] ] ...
uncompface [-X] [
infile [
outfile ] ] ...
DESCRIPTION¶
compface is a filter for generating highly compressed representations of
48x48x1 face image files.
uncompface is an inverse filter which
performs an inverse transformation with no loss of data. The algorithm used is
highly tuned for its purpose and achieves better than a five to one
compression ratio on average. Arguments operate identically for both
programmes. The first argument, if present, causes input to be taken from the
named file instead of from standard input unless it is the string ``-''. A
second argument, if present, causes output to go to the named file instead of
to standard output unless it is the string ``-''. Subsequent pairs of
arguments may be used to specify further pairs of input and output files.
The input format for
compface (and the output format for
uncompface) is 48 lines each of 3 sixteen bit hexadecimal integers,
comma terminated in C initialiser style. The output format of
compface
(and the input format for
uncompface) is some number of lines made up
of a space followed by printable characters (in the range ``!'' to ``~''
inclusive). The first line contains 72 characters and following lines contain
79 characters except that the last line may be short.
This version of compface has been patched to also be able to handle normal XBM
images. uncompface will produce XBM output only if the -X switch is applied.
The amount of compression obtained varies between face image files but the
output of
compface averages less than 200 characters. The average
number of output lines is three.
DIAGNOSTICS¶
Exit status is normally 0. Possible errors include IO errors when opening,
reading or writing files, format errors in
compface input files and
invalid arguments. Each results in an explanatory message on standard error
and an exit status of 1. A warning will be produced if
compface detects
extra input data.
BUGS¶
Nominating standard input as input more than once does not work.
SEE ALSO¶
Compface(3)