Reversible Data Hiding Using Two Marked Images Based on Adaptive Coefficient-Shifting Algorithm

Table 1

Three rules of data embedment for each host block.

Input block		Output (two) blocks
	Rule 1^∗ (BV <𝜏/3)	Rule 2^+ (𝜏/3 ≤ BV ≤𝜏)	Rule 3^† (BV >𝜏)
H	S1-A	S1-A	S1-C
	S2-A	S2-B	S2-C

*Both S1 and S2 were introduced by embedding data bits into H via the minimum-preserved scheme (A).
⁺S1 was introduced by embedding a secret message into H via the minimum-preserved scheme, and S2 was introduced by the BV embedding scheme (B).
^†Both S1 and S2 were introduced by embedding data bits into H via the minimum-preserved with squeezing scheme (C).