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compface, uncompface - compress and expand 48x48x1 face image files
compface [ infile [ outfile ] ] ...
uncompface [ infile [ outfile
] ] ...
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.
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.
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.
Nominating standard input as input more than once does not work.
Compface(3)
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