Table 2 The formulas to estimate the first five AC coefficients of each 
DCT block (2).
DCT block (2).From: A New Robust Watermarking Scheme to Increase Image Security
Featured blocks surrounded by horizontal featured blocks (Veeraswamy's method) | Featured blocks surrounded by vertical featured blocks (Veeraswamy's method) | Featured blocks surrounded by horizontal and vertical featured blocks (Veeraswamy's method) |
|---|---|---|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
