use MIME::Base64 qw(encode_base64 decode_base64);

#ENCODE
open(INBIN, "<:bytes","in.ico") or die "$!";
open(OUTB64, ">esc.b64") or die "$!";
binmode(INBIN);
while (read(INBIN, $buf, 60*57)) {
    print OUTB64 encode_base64($buf);
}
close (INBIN);
close (OUTB64);

#DECODE
open(OUTBIN, ">:bytes","out.ico") or die "$!";
open(INB64, "<esc.b64") or die "$!";
binmode(OUTBIN);
while (<INB64>) {
    print OUTBIN decode_base64($_);
}
close (OUTBIN);
close (INB64);