Mn-Ta Lee

Image copyright protection scheme using Sobel technology and genetic algorithm

A novel scheme combining Sobel technology with genetic algorithm is proposed in this paper to protect image copyright. For the Sobel-based copyright protection schemes in the literatures, they use Sobel technology to detect the edge of the cover image, i.e. the copyright image. By using the kernels to calculate the edge directions of the cover image, the gradients of the cover image pixels can be measured. When the gradient is greater than some scaling factor, which is used to control the robustness of the watermark, its corresponding pixel is considered to be an edge pixel. Otherwise, it is not an edge pixel. Therefore, how to decide a proper value for scaling factor is important for Sobel-based copyright protection schemes. In this paper, the genetic algorithm is used to provide optimal value for scaling factor. Experimental results are shown to demonstrate the robustness of the proposed scheme.

Robust Audio Watermarking Based on MDCT Coefficients

Multimedia contents can easily be replicated and spread in the Internet. for the verification of copyright of digital audio, digital watermark may be embedded in the audio. Compared with traditional watermarking technologies, zero-watermarking technology does not result in quality degradation, and thus can avoid the conflict between imperceptibility and robustness. in this paper, we calculate the bi-level characteristic sequence of audio signal by using the MDCT coefficients. Coupled with bi-level watermark image and the secrete key provided by an impartial third party, a private key is generated for subsequent intellectual property right verification of the copyright owner. to evaluate the robustness of the proposed zero-watermarking scheme, this study measured the accuracy of reconstructed watermark from audio signal after watermark attacks by various signal processing methods. the experimental results indicate that the proposed zero-watermarking method has better robustness as compared with methods proposed in literature. the proposed scheme is efficient and can be applied in the protection of intellectual property rights of audio signals.

Copyright protection scheme for still images based on an image pinned field

Watermark embedding processes usually result in some deg- radation of the digital multimedia contents. Hence, they are not suitable for valuable and sensitive digital multimedia contents. Therefore, schemes combining signature with digital watermarking-like techniques have been proposed. Based on the general model for these combined schemes, a new scheme for image copyright protection by utilizing the pinned field of the protected image is proposed in this paper. The pinned field explores the texture information of the images and can be used to enhance the watermark robustness. Experimental results show that the proposed scheme works well under different signal-processing and geo- metric transformation attacks. On the other hand, in comparison with related schemes in the literature, our proposed scheme also has better performance. Furthermore, the proposed scheme is robust to both JPEG lossy compression and additive Gaussian noise.

Watermarking Mechanism for Copyright Protection by Using the Pinned Field of the Pinned Sine Transform

Due to the rapid development of Internet, digital multimedia data are frequently transported on the Internet. Hence, how to protect important data from being stolen or modified has become an important issue. Digital watermarking can protect digital rights by embedding owner watermarks into the digital data, so the owner can declaim his ownership and intellectual property. In this paper, we propose a new watermarking method for image copyright protection by using the pinned field of the pinned sine transform of the protected image. The pinned field explores the texture information of the images and can be used to enhance the robustness of the watermark. Experimental results show that the proposed method can survive under different signal processing and geometric transformation attacks. Furthermore, our method is lossless because it does not modify the content of the protected image, and it does not need the original protected image during the authentication procedure.

Image Watermarking Using Phase-Shifting Digital Holography Embedded in the Wavelet Domain

In this paper, we propose a new watermarking scheme which combines both the digital holography and the digital watermarking techniques. The watermark is transformed into a digital phase-shifting hologram based on the Mach–Zehnder interferometer architecture and then is embedded into the specific subbands in the wavelet transform of the host image. By inversely transforming the wavelet coefficients in the subbands, the watermark can be successfully extracted with acceptable degradation. Simulations are performed to evaluate the performance of this new scheme.

Optical Security System by Using Image Dyadic Displacement and Manipulations in Fractional Fourier Domain

Most of the conventional optical security verification systems based on the domain of the fractional Fourier transform use a principal phase and fractional factors as keys. These systems will not be secure if the illegal users have the right phase key and know the fractional factors. Therefore, how to enhance the secure level of these systems is an important issue. A new architecture using the image dyadic displacement and manipulations to provide more parameters as supplementary keys is proposed. By using the image dyadic displacement to encrypt and decrypt the target image, as well as using the image manipulations, such as the image scaling factor and image interpolation methods to generate a dynamic lock, the security capability of the optical verification system is enhanced furthermore.

A neural network based coding mode selection scheme of hybrid audio coder

New generation mobile communication transfers multiple contents, thus, codec no longer processes specific audio signal content (speech or music) only, but has to process mixed audio signal content. As different audio signal types have different characteristics, they have to be processed by using proper coding core. Hybrid audio coder architecture can be adopted to improve the coding efficiency. The coder must determine signal type correctly in order to maintain the quality of decoded audio signal. The computational complexity of hybrid audio codec can be reduced if signal classification can be performed quickly. In this paper, a low complexity coding mode selection technique based on neural network has been investigated. The experimental results demonstrate that the proposed scheme enables a reduction of about 75 percent of the computational load of 3GPP AMR-WB+ coder. The degradation of SNR is about 0.4dB. The informal listening test shows that the quality degradation is almost negligible. The proposed scheme is more effective than the fast algorithm recommended in standard.

An ownership verification scheme by using image pinned field and genetic algorithm

As a result of explosive development of the Internet, digital contents can be convenient and fast exchanged on the Internet. Hence, how to protect important digital contents from being stolen or modified has become an important issue. In this paper, an optimal ownership verification scheme for image contents based on using both the pinned field of the protected image and the genetic algorithm is proposed. The pinned field explores the texture information of the protected image and can be used to enhance the robustness of the watermark. The genetic algorithm is then used to optimize the similarity between the texture information and the protected image. Experimental results show that the proposed scheme can survive under different signal processing and geometric transformation attacks.

Optical Verification System Based on a Correlator Using Image Manipulations as Locks

Most of optical security systems have a fixed lock and multiple keys to validate whether special users are legal or illegal. but those systems will be failed under the situation when the right keys are stolen by illegal users. This problem can be solved by providing multiple locks for the different users who want to access the optical security system. Therefore, a novel optical verification system based on a 4-f correlator combining with a lock database is proposed in this paper to enhance the security capability. Those locks in the lock database are generated by using multiple parameters, such as the image of organization logo, image compression format, image scaling factor, and image interpolation method. Only the user that knows the correct parameters described above and owns the right key can retrieve the corresponding lock from the lock database and has the ability to pass the verification of the security system.

On the pinned field image binarization for signature generation in image ownership verification method

The issue of pinned field image binarization for signature generation in the ownership verification of the protected image is investigated. The pinned field explores the texture information of the protected image and can be employed to enhance the watermark robustness. In the proposed method, four optimization schemes are utilized to determine the threshold values for transforming the pinned field into a binary feature image, which is then utilized to generate an effective signature image. Experimental results show that the utilization of optimization schemes can significantly improve the signature robustness from the previous method (Lee and Chang, Opt. Eng. 49(9), 097005, 2010). While considering both the watermark retrieval rate and the computation speed, the genetic algorithm is strongly recommended. In addition, compared with Chang and Lins scheme (J. Syst. Softw. 81(7), 1118-1129, 2008), the proposed scheme also has better performance.