In this paper, we introduce a multiresolution watermarking method for copyright protection of digital images. The method is based on the discrete wavelet transform. A noise type Gaussian sequence is used as watermark. To embed the watermark robustly and imperceptibly, w More
In this paper, we introduce a multiresolution watermarking method for copyright protection of digital images. The method is based on the discrete wavelet transform. A noise type Gaussian sequence is used as watermark. To embed the watermark robustly and imperceptibly, watermark components are added to the significant coefficients of each selected subband by considering the human visual system (HVS) characteristics. Some small modifications are performed to improve HVS model. The host image is needed in watermark extraction procedure and Normalized Correlation Function (NCF) is used to measure similarities of extracted watermarks. It is shown that this method is robust against wide variety of attacks such as: additive noise, low pass filtering, compression, chopping, histogram equalization, rotation. Comparison with other methods shows the better performance of this suggested method.
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In recent years, illegally copying digital images and even manipulating them, without great loss of quality and at a low cost has been made possible. Watermarking has recently been developed as one of the methods to detect that tampering has occurred and even enable som More
In recent years, illegally copying digital images and even manipulating them, without great loss of quality and at a low cost has been made possible. Watermarking has recently been developed as one of the methods to detect that tampering has occurred and even enable some recovery of the original images. However, there are still many issues to resolve in providing an effective watermark that can detect and recover a wide range of manipulations. Furthermore, the accuracy of detecting and the capability of the recovery of the original images by existing methods are still not at an acceptable level. These problems are more critical when certain high-rate manipulation attacks occur. In this paper, a watermarking method will be introduced that not only is able to detect any tampering, but also can successfully recover the original images in high quality, even at high tampering rates. In this method, Singular Value Decomposition (SVD) is used to detect tampering and Optimal Iterative Block Truncation Coding (OIBTC) has also been applied to recover lost data. This paper proposes a powerful way to increase detection sensitivity while increasing watermark resistance for the effective recovery of corrupted images. The results prove the superiority of the proposed method over current methods.92% of tasks are executed successfully in the edge environment.
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