#! perl -slw
use strict;
use Data::Dumper;

my %images;
$images{$1}{$2} = undef while <DATA> =~ m[copy_(\d+)_frag_(\d+)_id];
print Dumper \%images;

for my $copy ( 1 .. 9 ) {
	for my $frag ( 1 .. 9 ) {
		$images{$copy}{$frag} = int rand 100000
			if  exists $images{$copy}
			and exists $images{$copy}{$frag};
	}
}

print Dumper \%images;

__DATA__
copy_1_frag_1_id
copy_1_frag_2_id
copy_1_frag_3_id
copy_1_frag_4_id
copy_1_frag_5_id
copy_1_frag_6_id
copy_1_frag_7_id
copy_1_frag_8_id
copy_1_frag_9_id
copy_2_frag_3_id
copy_2_frag_5_id
copy_2_frag_7_id
copy_2_frag_9_id