Improved Digital Watermarking Using DWT Masking

Image watermarking on Gaussian low pass components ignoring edges and its neighbor pixels

“…According to the digital watermarking based on the modification of image pixels [4], the watermark image is to be XOR and converted the 0 bits into -1, so that the watermark becomes w(i,j)∈{-1,1} with the same resolution with the original image. The processed watermark then is to be multiplied with signal strength and the luminance value of the pixel.…”

“…Those techniques were balancing the watermark bits around the embedding pixels, tuning the strength of embedding watermark in according with the nearby luminance and reducing the bias in the prediction of the original image pixels from the surrounding watermarked image pixels. Recently, T. Pramoun et al [4] further improved the performance of the above watermarking method by fine tuning the watermark signal strength in the embedding process using the DWT Masking. We observed that the main problem normally encountered in the digital watermarking based on the modification of image pixels, as proposed in [1]- [4], is that the accuracy of the extracted watermark depends mainly on the variation of image pixels.…”

“…Recently, T. Pramoun et al [4] further improved the performance of the above watermarking method by fine tuning the watermark signal strength in the embedding process using the DWT Masking. We observed that the main problem normally encountered in the digital watermarking based on the modification of image pixels, as proposed in [1]- [4], is that the accuracy of the extracted watermark depends mainly on the variation of image pixels. For instance, the two neighbor pixels, having high different values causes error detection and effect significantly on the accuracy on watermark extraction.…”