Multi-Scale Difference Map Fusion for Tamper Localization Using Binary Ranking Hashing

High-Precision Authentication Scheme Based on Matrix Encoding for AMBTC-Compressed Images

“…Note that the bm (u, v) should not be used in the embedding procedure. In our experiments, (u, v) is set to (3,1), based on experimental results. We preprocess to check whether the h is equal to l. If it is, the bits in the bm are all equal to '1' and the preprocessing should thus be conducted; otherwise, nothing should be done.…”

“…Step 4. Extract the first seven bits of bm as the first cover vector, CV 1 = cv 1 1 , cv 1 2 , cv 1 3 , cv 1 4 , cv 1 5 , cv 1 6 , cv 1 7 = (bm (1,1) , bm (1,2) , bm (1,3) , bm (1,4) , bm (2,1) , bm (2,2) , bm (2,3) ). Extract the last seven bits of bm as the second cover vector, CV 2 = cv 2 1 , cv 2 2 , cv 2 3 , cv 2 4 , cv 2 5 , cv 2 6 , cv 2 7 = (bm (3,2) , bm (3,3) , bm (3,4) , bm (4, 1) , bm (4,2) , bm (4,3) , bm (4,4) ).…”

“…Similarly, Figure 2b presents a special case, i.e., h is equal to l and all bits in bm are 1. Thus, the preprocessing of the AMBTC compression code should be done, as described in Section 3.1; i.e., l is decreased by 1 and the bm (3,1) is set to 0. In this case, l and bm are slightly modified.…”

“…Also, two-tuple location information (g 1 = 2, g 2 = 5) will be derived and used as the to-be-hidden message in the following phase. The yellow grid represents the chosen bm (3,1) , as described in Section 3.1.…”

“…Researchers have conducted a series of scientific studies on image authentication. Roughly, authentication methods can be classified into two categories: Digital signature-based methods [1][2][3][4] and digital watermark-based methods . Generally, the digital signature-based method performs the encryption of the hashed results of the features of the image using a private key to form a unique signature, which will be used later for authentication.…”