As one of the important branches of quantum image processing, quantum image watermarking technology has been studied by many related personnel. However, most of them are performed in the time domain, and there are relatively few algorithms for quantum image watermarking in the transform domain. This paper proposes a quantum image watermarking technology based on quantum D4 wavelet transform, which specifically includes several aspects. Combining quantum wavelet transform and controlled-rotating gate, this paper proposed a quantum image watermarking algorithm for the modified flexible representation of quantum images (FRQIM) and the normal arbitrary superposition state (NASS). Firstly, the wavelet coefficients of the image are obtained by quantum wavelet transform, then the rotating gate is designed by the information of the watermark image, then the embedding position of the watermark image information is controlled by the controlled gate, and finally the watermark information is embedded in the carrier image by the controlled-rotating gate. This scheme makes full use of the parallelism of quantum computing and can operate on two images at the same time. The simulation results show that for different image combinations, the embedded image is not significantly different from the original image. Compared with the quantum image watermarking algorithm that uses the quantum Fourier transform, the image distortion after watermarking is smaller, and there are more options for embedding the image.
As one of the important branches of quantum image processing, quantum image watermarking technology has been studied by many related personnel. However, most of them are performed in the time domain, and there are relatively few algorithms for quantum image watermarking in the transform domain. This paper proposes a quantum image watermarking technology based on quantum D4 wavelet transform, which specifically includes several aspects. Combining quantum wavelet transform and controlled-rotating gate, this paper proposed a quantum image watermarking algorithm for the modified flexible representation of quantum images (FRQIM) and the normal arbitrary superposition state (NASS). Firstly, the wavelet coefficients of the image are obtained by quantum wavelet transform, then the rotating gate is designed by the information of the watermark image, then the embedding position of the watermark image information is controlled by the controlled gate, and finally the watermark information is embedded in the carrier image by the controlled-rotating gate. This scheme makes full use of the parallelism of quantum computing and can operate on two images at the same time. The simulation results show that for different image combinations, the embedded image is not significantly different from the original image. Compared with the quantum image watermarking algorithm that uses the quantum Fourier transform, the image distortion after watermarking is smaller, and there are more options for embedding the image.
In this paper, a novel frequency domain quantum watermarking scheme is proposed based on the Flexible Representation of Quantum Images, which can embed a 2n1× 2n1binary watermark image into a 2n× 2ngrayscale carrier image. The quantum Haar wavelet transform is developed and used to decompose quantum images. The diagonal detail coefficients of the carrier image are obtained from the image decomposition. Then, according to the watermark image information, the diagonal wavelet coefficients are either unchanged or slightly modified. Since all of the used quantum operations are invertible, extraction of the watermark image is performed in a straightforward manner by reversing the watermarking embedding process. Finally, the proposed quantum image watermarking scheme is simulated on a classical computer and evaluated under different carrier and watermark images. The simulation results and performance analyses indicate the high performance of the presented watermarking scheme in terms of the similarity between the watermarked and carrier images.
This paper presents a spatial domain quantum watermarking scheme. For a quantum watermarking scheme,a feasible quantum circuit is a key to achieve it. This paper gives a feasible quantum circuit for the presented scheme. In order to give the quantum circuit, a new quantum multi-control rotation gate, which can be achieved with quantum basic gates, is designed. With this quantum circuit, our scheme can arbitrarily control the embedding position of watermark images on carrier images with the aid of auxiliary qubits. Besides reversely acting the given quantum circuit, the paper gives another watermark extracting algorithm based on quantum measurements. Moreover, this paper also gives a new quantum image scrambling method and its quantum circuit. Differ from other quantum watermarking schemes, all given quantum circuits can be implemented with basic quantum gates. Moreover, the scheme is a spatial domain watermarking scheme, and is not based on any transform algorithm on quantum images. Meanwhile, it can make sure the watermark be secure even though the watermark has been found. With the given quantum circuit, this paper implements simulation experiments for the presented scheme. The experimental result shows that the scheme does well in the visual quality and the embedding capacity.
Abstract This paper presents a spatial domain quantum watermarking scheme. For a quantum watermarking scheme, a feasible quantum circuit is a key to achieve it. This paper gives a feasible quantum circuit for the presented scheme. In order to give the quantum circuit, a new quantum multi-control rotation gate, which can be achieved with quantum basic gates, is designed. With this quantum circuit, our scheme can arbitrarily control the embedding position of watermark images on carrier images with the aid of auxiliary qubits. Besides reversely acting the given quantum circuit, the paper gives another watermark extracting algorithm based on quantum measurements. Moreover, this paper also gives a new quantum image scrambling method and its quantum circuit. Differ from other quantum watermarking schemes, all given quantum circuits can be implemented with basic quantum gates. Moreover, the scheme is a spatial domain watermarking scheme, and is not based on any transform algorithm on quantum images. Meanwhile, it can make sure the watermark be secure even though the watermark has been found. With the given quantum circuit, this paper implements simulation experiments for the presented scheme. The experimental result shows that the scheme does well in the visual quality and the embedding capacity.
Information and Communication Technology (ICT) has significantly developed nowadays, making things easier for users. However, alongside the ease of communication, several concerns arise, particularly regarding data authenticity. Security, which affects the authenticity of data, is a major concern. Quantum watermarking offers a much better solution for this problem in the next generation of technology, as it provides superior security compared to classical watermarking. In this paper, we propose a quantum watermarking method using Taylor sequence modification and rotation gates for watermark embedding. Before the embedding process, we convert the images into the quantum domain using the Flexible Representation of Quantum Images (FRQI). We then calculate the phase representation of the host and watermark pixels. Using a Taylor sequence, we modify the watermarked phase and calculate the difference between the host and watermarked phases. Several rotation gates are used to modify the host phase on the quantum circuit. At the end of the embedding process, we reconstruct the watermarked quantum images into a classical images. The experimental results demonstrated watermarking imperceptibility, represented by Peak Signal to Noise Ratio-H (PSNR-H) and watermark robustness, represented by Peak Signal to Noise Ratio-W (PSNR-W). The PSNR-H values ranged between 10–80 dB, while the PSNR-W values reached up to 20 dB. This proposed method has a unique outcome even when the PSNR-H value is infinite, the watermark can still be detected and is subjectively visible to the human eye.
A universal watermarking protocol for quantum images is designed in this paper. The protocol is developed based on quantum transform (QT) and quantum add operation (QAO). Moreover, a dynamic vector is introduced to control the embedding strength in the embedding process, which is obtained through the constraint that quantum image state should keep normalized in the entire computation process. Therefore, the dynamic vector is an optimal solution of an optimization equation, which makes the watermarked image with better visual quality. Compared with the other protocols or schemes, the proposed one can improve watermarking performance of visual quality and capacity. Experiments based on flexible representation of quantum image (FRQI) and Quantum Fourier transform (QFT) illustrate the superior effectiveness of the proposed protocol.
Quantum image watermarking technology is influenced by embedding algorithm, which permanently distorts the embedded quantum carrier image.To protect and authenticate quantum images without damaging the carrier images, this study proposed a quantum image reversible watermarking algorithm combining the most significant qubit (MSQb) and the least significant qubit (LSQb).First, a binary watermark image, a grayscale carrier image, and an empty key image were represented using the novel enhanced quantum representation of digital images.Second, the encrypted qubit of the binary watermark image was matched with the MSQb of the carrier image.If they were equal, then the high qubit of the quantum key image was flipped.Otherwise, the encrypted qubit of the binary watermark image was matched with the XOR value of the lowest two qubits of the carrier image.The LSQb of the carrier image was modified according to the matching result.Finally, the quantum watermarked image was obtained.Simulation experiments and theoretical analysis verified the feasibility and watermark performance of the scheme.Results demonstrate that the scheme achieves correct extraction of quantum image watermark and lossless restoration of original image.The visual quality PSNR of the carrier image embedded with watermark through the scheme is improved by approximately 4% compared with that through the traditional LSQb method.The study provides a reference for studying and implementing reversible image watermarking technology in the era of quantum computer, which can be applied to harsh copyright protection and authentication of the visual quality of the original carrier image.