A more secure steganography based on adaptive pixel-value ...

Multimed Tools Appllocated at the content edges whose strength degree is larger than T, theng i+1can be used for data embedding:Determine the range of centre pixel in the embedding unit, denoted as range g ′i+1,which satisfies that the sort order of g i , gi+1 ′ , g i+2 in the stego is the same asthe sort order of g i , g i+1 , g i+2 in the cover, also the relationships between d 1 , d 2(d ′ 1 , d′ 2 )andT are preserved after data hiding. For instance, if g i ≥ g i+1 ≥ g i+2in the cover, then we have g i ≥ gi+1 ′ ≥ g i+2 in the stego, if |d 1 |=|g i+1 − g i | > T,then we keep |d ′ 1 |=|g′ i+1 − g i| > T.The range can be obtained according to the following four cases:– Case 1 g i+1 < g i and g i+1 < g i+2 ,case 1.1:if |d 1 | > T & |d 2 | > Trange g ′i+1= [ 0,...,min ( g i − T − 1, g i+2 − T − 1 )]case 1.2:case 1.3:if |d 1 | > T & |d 2 |≤Trange g ′i+1= [ max ( g i+2 − T, 0 ) ,...,min ( g i − T − 1, g i+2 − 1 )]if |d 1 |≤T & |d 2 | > Trange g ′i+1= [ max ( g i − T, 0 ) ,...,min ( g i+2 − T − 1, g i − 1 )]– Case 2 g i+1 > g i and g i+1 > g i+2 ,case 2.1:if |d 1 | > T & |d 2 | > Trange g ′i+1= [ max ( g i + T + 1, g i+2 + T + 1 ) ,...,255 ]case 2.2: if |d 1 | > T & |d 2 |≤Trange g ′i+1= [ max ( g i + T + 1, g i+2 + 1 ) ,...,min ( g i+2 + T, 255 )]case 2.3:if |d 1 |≤T & |d 2 | > Trange g ′i+1= [ max ( g i+2 + T + 1, g i + 1 ) ,...,min ( g i + T, 255 )]– Case 3 g i ≥ g i+1 ≥ g i+2case 3.1:case 3.2:case 3.3:if |d 1 | > T & |d 2 | > Trange g ′i+1= [ g i+2 + T + 1,...,g i − T − 1 ]if |d 1 | > T & |d 2 |≤Trange g ′i+1= [ g i+2 ,...,min ( g i+2 + T, g i − T − 1 )]if |d 1 |≤T & |d 2 | > Trange g ′i+1= [ max ( g i+2 + T + 1, g i − T ) ],...,g i– Case 4 g i ≤ g i+1 ≤ g i+2case 4.1:if |d 1 | > T & |d 2 | > Trange g ′i+1= [ g i + T + 1,...,g i+2 − T − 1 ]