NAME

       compface, uncompface - compress and expand 48x48x1 face image files

SYNOPSIS

       compface (buf)

       uncompface (buf)

       char *buf

DESCRIPTION

       compface  is  a  function  for  generating highly compressed representations of 48x48x1 face image files.
       uncompface is an inverse function 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.  In both functions, input is via a NULL terminated string and a NULL terminated output string
       is written over the input string.  Buf should therefore point to a block of 2K  size  or  more  to  avoid
       buffer overruns during output generation.

       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

       The  return  value  is  normally 0.  1 will be returned if extra input has been ignored during a compress
       operation.  -1 is returned in the case of an invalid input format.  -2 is returned if an internal  buffer
       overrun occurs.

SEE ALSO

       Compface(1)

                                                 25 January 1990                                     COMPFACE(3)