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)