#! /usr/sbin/perl

#---------------------------------------------------------------------

#	Copyright (C) 1997, Nintendo.

#	

#	File		ppm8to5.perl

#	Coded    by	Yoshitaka Yasumoto.	Apr 10, 1997.

#	Modified by	

#	Comments	

#	

#	$Id: ppm8to5.perl,v 1.1.1.1 2003/01/17 23:03:22 wheeler Exp $

#---------------------------------------------------------------------

#

#  [How to use]

#	perl ppm8to5.perl < infile > outfile

#

#	Round-off 8 bit RGB to 5 bit RGB.

#



# Analyze the ppm file header

$i = 0;

while (<STDIN>){

	s/#.*$//;	# Comment process

	s/^\s+//;	# Removes spaces

	while (s/^\S+//){

		$param[$i ++] = $&;	# Saves parameters

		s/^\s+//;		# Removes spaces

	}	

	last if ($i == 4);

}

die "This is not P6 ppm format!!\n" if ($param[0] ne "P6");



$width  = $param[1];

$height = $param[2];

$pixel  = $param[1] * $param[2];



printf("P6\n%d %d\n255\n", $width, $height);



for ($i = 0; $i < $pixel; $i ++){



    # Get the data for 1 Pixel

    read(STDIN, $buf, 3) == 3 || die "Too short file\n";

    @tmp = unpack("C3", $buf);

    

    # Get the color value

    $tmp[0] &= 0xf8;

    $tmp[1] &= 0xf8;

    $tmp[2] &= 0xf8;



    # Convert to binary

    $buf = pack("C3", @tmp);    

	    

    # Output

    print $buf;

}



#======== End of ppm8to5.perl ========