Noise verification

Different from proof of ownership schemes [2], [3], the verification of watermark requires a key. Given an image $J$ and a verification key $K_{\mathtt{verif}}$, we first try to recover a watermark $\hat{W}$ from $J$ using a decoding function $\mathcal{D}$:

$$\hat{W} = \mathcal{D} \thinspace (J, K_{\mathtt{verif}})$$

Next $\hat{W}$ is compared against $W$, if the deviation is above some threshold $T$:

$$\lVert \hat{W} - W \rVert \geq T$$

then $J$ will be accepted otherwise rejected.

Noise verification