a> some random text ---------------- b> b> a few random b> lines b> b> of more b> random b> b> text **************** c> some more c> c> random c> text c> a> some random text ---------------- b> b> a few random b> lines b> b> of more b> random b> b> text **************** c> some more c> c> random c> text c> ##

##

@foo = (
    {
        a => 'some random text'
        b => 
'
a few random
lines

of more 
random

text
'
        c => 
'some more 

random
text
'
    },
     {
        a => 'some random text'
        b => 
'
a few random
lines

of more 
random

text
'
        c => 
'some more 

random
text
'
    },
    .. and so on ..
);

##

##

   bri    red    grn    blu
     0      0      0      0
     1      0      0      0
     2      0      0      0
..
    99      0      0      0
   100      0    255    255
   101      0    250    255
   102      0    246    255
..

##

##

CLASS
    EXPRESSION ([pixel] >= 242 AND [pixel] <= 242
    STYLE
        COLOR 200 72 127
    END
END
CLASS
    EXPRESSION ([pixel] >= 175 AND [pixel] <= 175
    STYLE
        COLOR 191 236 0
    END
END
..

##

##

while () {

    # remove leading whitespace & newline from end
    # and split the row on whitespace
    my @r = chomp && s/^\s+// && split /\s+/;
    
    # create a key in lut hash using rgb vals
    push @{$lut{"$r[1].$r[2].$r[3]"}}, $r[0];
}

while (my ($k, $v) = each %lut) {
    $k =~ s/\./ /g;     # replace . in hash key with space
    my @v = sort @$v;   # sort the color brightness array to get 
                        # min/max values
    
    print OUTFILE 
       "CLASS\n" . 
       "    EXPRESSION ([pixel] >= $v[0] AND [pixel] <= $v[$#v]\n" . 
       "    STYLE\n" . 
       "        COLOR $k\n" . 
       "    END\n" . 
       "END\n";
}