In this paper, we apply the DCT-DWT algorithm to produce a novel video watermark scheme. A comparison experiment between the proposed algorithm and DCT-DWT-SVD algorithm is shown here. The DCT-DWT-SVD algorithm uses DWT first to choose the HH sub-band, then applies the DCT algorithm to the HH sub-band, and uses SVD to embed the watermark signal. In this section, we test the robustness of the proposed hybrid algorithm. Tempete.yuv and Football.yuv, as the standard video templates are applied in this section. Tempete.yuv shows the leaves swing and Football.yuv shows the football sports. The dimension of the host video frame is 288×352 pixels and the watermark image is sized by 32×32. The maximum embedding capacity is 101376 coefficients. The embedding strength ɑ is 1.0. Fig. 7 shows the first frames of the host video and watermarked content. In this section, the peak signal to noise ratio (PSNR) and normalized correlation (NC) are used to describe the experiment result. PSNR is always used to describe the similarity between the original and watermarked images, while NC is always used to compare the original and extracted watermarks.
To measure the quality between the original video frame and the watermarked video frame, PSNR is applied, as
where MSE represents the mean square error and is presented as below:
If PSNR is greater than 30, it means the transparency of the watermarked video frame keeps the similarity as the host video frame. Therefore, Table 1 shows the PSNR values between the original video frame and the watermarked video frame. Fig. 7 shows the images of them. As can be seen in Table 1, the proposed algorithm gets larger PSNR values than the DCT-DWT-SVD algorithm. In addition, we also find that the watermark signal is successfully embedded into the original video frame and the properties of transparency are not affected.
Algorithms PSNR Tempete.yuv Football.yuv Proposed algorithm 39.6583 39.3984 DCT-DWT-SVD algorithm 36.8561 37.1426
Table 1. PSNR between the original and watermarked video frames
In addition, the NC value is always used to compare the similarity between the extracted watermark signal and the original watermark signal. The range of the NC value is between 0.0 and 1.0. The formula of NC is shown as
If the NC value closes to 1.0, it represents that the extracted watermark content is similar to the original watermark. The comparison of the original watermark content and the extracted watermark content is shown in Fig. 8. Table 2 compares the NC values of the proposed algorithm with that of the other one. As that can be seen in Table 2, we find the quality of the extracted watermarks obtained from the proposed algorithm is better than that of the DCT-DWT-SVD algorithm.
Algorithms NC values Tempete.yuv Football.yuv Proposed algorithm 0.9985 0.9982 DCT-DWT-SVD algorithm 0.8134 0.7805
Table 2. NC between original and extracted watermarks
This part tests the robustness of the proposed algorithm under different watermarking attacks. There are six watermarked attacks proposed in the experiment, they are the Poisson attack, salt-pepper filter attack, Gaussian filter attack, cutting frames attack, sharpen attack, and enlarge and revert attack. The severity of these attacks can be adjusted by modifying their corresponding parameter values. The watermarked video frame in Fig. 7 (b) is suffered from these attacks and the corresponding extracted watermarks are shown in Fig. 9. The comparison of NC values between the proposed and original algorithms is shown in Table 3.
Figure 9. Extracted watermarks after (a) Poisson filter attack, (b) salt-pepper filter (0.02) attack, (c) Gaussian filter (0.05) attack, (d) cutting frames (5) attack, (e) cutting frames (10) attack, (f) sharpening (linear) attack, and (g) enlarge and revert (2) attack.
Attack mode NC values Tempete.yuv Football.yuv Proposed algorithm DCT-DWT-SVD algorithm Proposed algorithm DCT-DWT-SVD algorithm Poisson filter 0.9843 0.6025 0.9780 0.5925 Salt-pepper filter (0.02) 0.9644 0.5934 0.9655 0.5875 Gaussian filter (0.05) 0.9258 0.5916 0.9333 0.5954 Cutting frames (5) 0.9663 0.8251 0.9670 0.7869 Cutting frames (10) 0.8881 0.7363 0.8951 0.7347 Sharpening (linear) 0.9978 0.6089 0.9985 0.6358 Enlarge and revert (2) 0.8903 0.4121 0.8913 0.3929
Table 3. NC values under different attacks
As shown in Fig. 9, the watermark is extracted successfully after different watermark attacks, the results in Tables 1, 2, and 3 are also provided the similar conclusion. In addition, we find that most of the NC values are over 0.9, it indicates the proposed algorithm can overcome several different attacks. In addition, from the inspection of Table 3, we find that the proposed technique is significantly more robust to attacks than the compared algorithm. This DCT-DWT-SVD algorithm could not resist against various watermark attacks due to the use of the HH sub-band which makes it relatively easy to be attacked. We can also argue that the robustness of our hybrid algorithm is greater than that of another algorithm under different attacks.
Robust Video Watermarking Using a Hybrid DCT-DWT Approach
- Received Date: 2016-08-31
- Rev Recd Date: 2017-02-25
- Available Online: 2020-07-08
- Publish Date: 2020-06-01
Abstract: In order to solve the limitations of the digital video watermarking algorithm, this paper proposes a new robust video watermarking algorithm using combining discrete cosine transform (DCT) and discrete wavelet transform (DWT) techniques. First of all, the video frames are randomly selected and then the DCT algorithm is applied to the selected video frames. After that, the first column of the selected video frames is scrambled using the Arnold algorithm. Furthermore, every column with 4 direct current (DC) coefficients is reshaped and transformed into four different sub-bands using the DWT technique. Next, the watermark is embedded into the approximation (LL) sub-band. The proposed algorithm is easy to carry out because it provides random frames with no special requirements for video frames. The experiment results indicate that this algorithm can resist against different kinds of watermarking attacks, such as the Gaussian filter attack and sharpen attack. In addition, it also illustrates that the proposed algorithm has a better result than some other watermarking algorithms.
|Citation:||Jie Sang, Qi Liu, Chun-Lin Song. Robust Video Watermarking Using a Hybrid DCT-DWT Approach[J]. Journal of Electronic Science and Technology, 2020, 18(2): 179-189. doi: 10.1016/j.jnlest.2020.100052|