Watermarked Blocks Research Articles

ZWNet: A Deep-Learning-Powered Zero-Watermarking Scheme with High Robustness and Discriminability for Images

In order to safeguard image copyrights, zero-watermarking technology extracts robust features and generates watermarks without altering the original image. Traditional zero-watermarking methods rely on handcrafted feature descriptors to enhance their performance. With the advancement of deep learning, this paper introduces “ZWNet”, an end-to-end zero-watermarking scheme that obviates the necessity for specialized knowledge in image features and is exclusively composed of artificial neural networks. The architecture of ZWNet synergistically incorporates ConvNeXt and LK-PAN to augment the extraction of local features while accounting for the global context. A key aspect of ZWNet is its watermark block, as the network head part, which fulfills functions such as feature optimization, identifier output, encryption, and copyright fusion. The training strategy addresses the challenge of simultaneously enhancing robustness and discriminability by producing the same identifier for attacked images and distinct identifiers for different images. Experimental validation of ZWNet’s performance has been conducted, demonstrating its robustness with the normalized coefficient of the zero-watermark consistently exceeding 0.97 against rotation, noise, crop, and blur attacks. Regarding discriminability, the Hamming distance of the generated watermarks exceeds 88 for images with the same copyright but different content. Furthermore, the efficiency of watermark generation is affirmed, with an average processing time of 96 ms. These experimental results substantiate the superiority of the proposed scheme over existing zero-watermarking methods.

Non‐redundant frame identification and keyframe selection in DWT‐PCA domain for authentication of video

This study is intended to protect video data and watermark from unauthorised access. The proposed methodology accentuates two new algorithms, namely structural similarity index metric–absolute difference metric (SSIM-AMD) based non-redundant frame identification (NRFI) and entropy–AMD based keyframe selection (KFS) to reduce the challenges posed by traditional discrete wavelet transform–singular value decomposition. Traditional techniques embed the entire watermark to all existing frames in the video, which is cumbersome and time-consuming. In this methodology, NRFI algorithm is applied to segregate the redundant and non-redundant frames to specific database. The KFS algorithm is used to identify suitable keyframes. DWT is applied into keyframes, which decomposes the frames into subbands. The middle band is selected for embedding. The principal component of watermark image block is embedded into identified keyframes in the video. The chaotic map is adapted to reorder the watermark block for improving the authentication level of the watermarking. The ant colony optimization (ACO) technique is adapted to select the suitable scaling factor for watermarking process. The principal component analysis technique is employed for avoiding false-positive attacks. Experimental results show the proposed methodology can withstand image processing, video processing, false-positive attacks and produces good results in terms of perceptual quality and robustness.

Fibonacci Based Key Frame Selection and Scrambling for Video Watermarking in DWT–SVD Domain

Video copyright is the technique for hiding sensitive data in digital video. This paper aims to introduce a new technique for video copyright namely Fibonacci based keyframe selection and scrambling for video watermarking in DWT---SVD. In this methodology, scene change detection technique is employed for identifying frequent changes in the scenes. In a specific frame, each scene is selected by using keyframes, which are generated by Fibonacci sequence. The initial seeds of the Fibonacci sequence are used as authentication key for generating keyframes. Based on the limitations of the scene changes the authentication keys are generated. The watermark is embedded only in specific frame of the changed scene in LH sub band. The secret image is scrambled using Fibonacci---Lucas transform. In embedding process, singular values (SVs) of the scrambled watermark block are added to the SVs of specific frames, produce the watermarked video collectively. In extraction phase, SVD is performed on the watermarked video to extract the scrambled watermark block from key frames. After that the extracted watermark blocks are collected together to yield the complete scrambled watermark. Later it is descrambled by using the secret keys to generate the original watermark. This method is blind since the host video is not required to extract the watermark. The experimental results show that the proposed methodology resists different image and video processing attacks. In addition, the proposed methodology improves the robustness and quality of both host video and watermark.

An SVD Based Location Specific Robust Color Image Watermarking Scheme Using RDWT and Arnold Scrambling

In recent times, effectiveness of the robust image watermarking scheme almost successfully solves the authenticity and copyright protection problem of images. Among several existing robust watermarking schemes, very few have been designed for color images. In this paper, the authors have proposed a redundant discrete wavelet transform (RDWT) and singular value decomposition based hybrid robust color image watermarking method where scrambled watermark is used for embedding purpose to provide extra security to authentic logo. At first, RGB color image is converted to YCbCr color image and then the Y component of YCbCr color space is used to insert Arnold scrambled grayscale watermark. In the next step, Y component of the YCbCr color model is decomposed into non overlapping blocks and subsequently RDWT are applied to each block. For better imperceptibility and effectiveness, in this proposed algorithm some singular values of RDWT transformed Y component blocks are modified by non overlapping decomposed and scrambled watermark blocks. Robustness of the proposed method is experimented against common geometric transformation attacks (like rotation, flip operation, cropping, scaling, shearing and deletion of lines or column operation etc.), common enhancement technique attacks (like lowpass filtering, histogram equalization, sharpening, gamma correction, noise addition etc.), jpeg compression attacks, some combinational attacks and satisfactory results are achieved. For better evaluation, proposed scheme is verified against standard benchmark software “Checkmark”.

Multiresolution Video Watermarking Algorithm Exploiting the Block-Based Motion Estimation

This paper presents a novel technique for embedding a digital watermark into video frames based on motion vectors and discrete wavelet transform (DWT). In the proposed scheme, the binary image watermark is divided into blocks and each watermark block is embedded several times in each selected video frame at different locations. The block-based motion estimation algorithm is used to select the video frame blocks having the greatest motion vectors magnitude. The DWT is applied to the selected frame blocks, and then, the watermark block is hidden into these blocks by modifying the coefficients of the Horizontal sub-bands (HL). Adding the watermark at different locations in the same video frame makes the scheme more robust against different types of attacks. The method was tested on different types of videos. The average peak signal to noise ratio (PSNR) and the normalized correlation (NC) are used to measure the performance of the proposed method. Experimental results show that the proposed algorithm does not affect the visual quality of video frames and the scheme is robust against a variety of attacks.

Compressed Watermarked Video Frame Transmission System Using Chaotic Interleaving

In this paper, we propose a chaotic Baker interleaving approach for efficient spiht compressed steganography watermarked frame of transmission of video over (OFDM) wireless systems with equalization. Cases of Rayleigh fading channels and additive white Gaussian noise are considered. The spiht compressed steganography watermarked video frames is primarily converted to approach of chrominance and after that the chrominance approach is converted to a binary data format. Prior to the modulation step made interleaving on the binary data. The proposed chaotic interleaving approach made reducing in the channel effects on the data which it is transmitted and made adding a degree of encryption to the transmitted data. The big data of the video frames is reduced by madding spiht compressed technique. To test the performance of the proposed approach by the transmission of spiht compressed steganography watermarked video various frames over additive white Gaussian noise and Rayleigh fading channels with interleaving by chaotic baker map. The results of the experiments explain that the received compressed steganography watermarked video frames are gives higher peak signal to noise ratios (PSNRs) with applied chaotic interleaving compared with other approaches and also show the histogram count of the correlation coefficient of the watermarked blocks.

Image adaptive DCT- SVD based digital watermarking scheme by human visual characteristics

The paper proposes an efficient watermarking scheme by incorporating singular valuedecomposition (SVD), discrete cosine transform (DCT) and homogeneity informationin the carrier image. The algorithm decomposes the carrier and watermark images intonon-overlapping blocks and analyzes the homogeneity of pixels in them to identify thepossible blocks of carrier image where the suitable watermark block can be attached sothat the watermarking process maintain better visual image fidelity in the watermarkedimage. The algorithm avoids the decomposed high frequency carrier image blockswhile attaching watermark blocks to reduce the visual distortion in the watermarkedimages. Experimental results show that the proposed algorithm produces good qualitywatermarked images and are less immune to potential attacks.

BLOCK-PARALLEL SYSTOLIC-ARRAY ARCHITECTURE FOR 2-D NTT-BASED FRAGILE WATERMARK EMBEDDING

Number-theoretic transforms (NTTs) have been applied in the fragile watermarking of digital images. A block-parallel systolic-array architecture is proposed for watermarking based on the 2-D special Hartley NTT (HNTT). The proposed core employs two 2-D special HNTT hardware cores, each using digital arithmetic over GF(3), and processes 4 × 4 blocks of pixels in parallel every clock cycle. Prototypes are operational on a Xilinx Sx35-10ff668 FPGA device. The maximum estimated throughput of the FPGA circuit is 100 million 4 × 4 HNTT fragile watermarked blocks per second, when clocked at 100 MHz. Potential applications exist in high-traffic back-end servers dealing with large amounts of protected digital images requiring authentication, in remote-sensing for high-security surveillance applications, in real-time video processing of information of a sensitive nature or matters of national security, in video/photographic content management of corporate clients, in authenticating multimedia for the entertainment industry, in the authentication of electronic evidence material, and in real-time news streaming.

PERFORMANCE EVALUATION OF BLOCK BASED SVD IMAGE WATERMARKING

This paper presents a block based digital image watermarking algorithm that is dependent on the mathematical technique of singular value decomposition (SVD). Traditional SVD watermarking already exists for watermark embedding on the image as a whole. In the proposed approach, the original image is divided into blocks, and then the watermark is embedded in the singular values (SVs) of each block, separately. The watermark embedding on a blockby-block basis makes the watermark more robust to the attacks such as noise, compression, cropping and lowpass filtering as the results reveal. The watermark detection is implemented by extracting the watermark from the SVs of the watermarked blocks. Extracting the watermark from one block at least is enough to ensure the existence of the watermark.

Analysis of position based watermarking

This paper extends the position based watermarking (PBW) technique introduced by Borges and Mayer (Position based watermarkings, 2003) and provides a detailed performance analysis considering additive white Gaussian noise and collusion attacks. We significantly improve the tradeoff between fidelity and robustness of our previous research on this subject by exploiting the informed embedding and informed coding paradigms. In contrast to traditional watermarking approaches such as least significant bit embedding, spread spectrum modulation and dirty paper codes, the content of the embedded watermark blocks do not need to carry information. Our unique approach maps the information according to specific locations in the image where we embed small watermark blocks. We provide theoretical analyses and experimental results to compare with the performance of the spread spectrum technique. These analyses and experiments confirm our superior tradeoff between robustness and transparency and also show the superior robustness of PBW to collusion attacks.

Effectiveness of tensiometers and electrical resistance sensors varies with soil conditions

Tensiometers, gypsum blocks, Watermark blocks and an electromagnetic conductivity meter were evaluated for their response to changes in soil moisture content. Tensiometers and Watermark blocks had similar responses, but the blocks operated better than tensiometers in drier soil. Gypsum blocks did not respond until some threshold moisture content was reached. The electromagnetic conductivity meter responded to changes in moisture content in fine-textured soil, but it did not respond in sandy soil.