#!/usr/bin/perl

my ($previous_key, $previous_line);
open my $IN, "<", '/home/scripts/imageoutcome.txt' or die "cannot open $infile $!";
while (<$IN>) {
    my $key = $1 if /^(\w+)/;
    if ($key eq $previous_key) {
        print $previous_line if defined $previous_line;
        print $_;
        undef $previous_line;
    } else {
        $previous_line = $_;
    }
    $previous_key = $key;
}