Figures

Figure 2: The autocorrelation of $d$.

Figure 3: The ratio of two successive periods of the mark.

Figure 4: Output of our detection algorithm with $p=30$ on the original song $A$ and its marked counterpart $AM$.

Figure 5: Output of our detection algorithm with $p=30$ on our newly produced song $C$ and its marked counterpart $B$.

Figure 6: Output of our detection algorithm with $p=450$ on the four songs $A,AM,B$ and $C$.

Figure 7: Comparison between the mark recovered from the difference $D=AM-A$ and the mark recovered from $BM$.

Figure 8: Comparison between $S[j]$ and $S'[j]-S[j]$ in the frequency domain. Note that most of the energy of $S[j]$ is contained in the low frequency