Temporal Synchronization Attacks Research Articles

Robust Video Watermarking Scheme Based on Intra-Coding Process in MPEG-2 Style

The proposed scheme implemented a semi blind digital watermarking method for video exploiting MPEG-2 standard. The watermark is inserted into selected high frequency coefficients of plain types of discrete cosine transform blocks instead of edge and texture blocks during intra coding process. The selection is essential because the error in such type of blocks is less sensitive to human eyes as compared to other categories of blocks. Therefore, the perceptibility of watermarked video does not degraded sharply. Visual quality is also maintained as motion vectors used for generating the motion compensated images are untouched during the entire watermarking process. Experimental results revealed that the scheme is not only robust to re-compression attack, spatial synchronization attacks like cropping, rotation but also strong to temporal synchronization attacks like frame inserting, deleting, swapping and averaging. The superiority of the anticipated method is obtaining the best sturdiness results contrast to the recently delivered schemes.

Video Watermarking Scheme Based on Candidates I-frames for Copyright Protection

<p>This paper focuses on moving picture expert group ( MPEG) based digital video watermarking scheme for copyright protection services. The present work implemented the video watermarking technique in which discrete cosine transform (DCT) intermediate frequency coefficients from instantaneous decoder refresh (IDR) frames are utilized. The subset of IDR frames as candidate frames are chosen to reduces the probability of temporal synchronization attacks to achieve better robustness and high visual perceptual quality. A secret key based cryptographic technique is used to enhance the security of embedded watermark. The proposed scheme embedded the watermark directly during the differential pulse code modulation (DPCM) process and extracting through decoding the entropy details. Three keys are required to extract the watermark whereas one of the key is used to stop the extraction process and the remaining two are used to display the watermark. The robustness is evaluated by testing spatial synchronization attacks, temporal synchronization attacks and re-encoding attacks. The present work calculates the simulation results that shows the watermarking scheme achieved high robustness against video processing attacks frequently occur in the real world and perceptibility also obtained without changing the motion vectors during the DPCM process of MPEG-2 encoding scheme.</p>

Imperceptible and Robust Blind Video Watermarking Using Chrominance Embedding: A Set of Approaches in the DT CWT Domain

Illegal distribution of a digital movie is a significant threat to the film industries. With the advent of high-speed broadband Internet access, a pirated copy of a digital video can be easily distributed to a global audience. Digital video watermarking is a possible means of limiting this type of digital distribution. In existing watermarking methods, the watermark is usually embedded into the luminance channel of a video frame, which affects imperceptibility. In addition, none of the existing techniques are robust to the combination of commonly used attacks, such as compression, upscaling, rotation, cropping, downscaling in resolution, frame rate conversion, and camcording. In this paper, we initially propose a basic blind digital video watermarking algorithm, where the watermark is embedded into one level of the dual-tree complex wavelet transform of the chrominance channel to provide high quality watermarked video and extracted using the same key that was used for embedding. This algorithm is robust to compression, upscaling, rotation, and cropping. An extension of this method extracts the watermark from any level(s) of the dual-tree complex wavelet transform depending on the resolution of the downscaled version of the watermarked frame rather than only from the embedding level to survive downscaling to an arbitrary resolution. Finally, the watermark of a frame is extracted from the information of that frame without using the key that was used during watermark embedding to provide robustness to temporal synchronization attacks, such as frame rate conversion. This scheme is also robust to compression, camcording, watermark estimation remodulation, temporal frame averaging, multiple watermark embedding, downscaling in resolution, and other geometric attacks, such as upscaling, rotation, and cropping.

A robust video watermarking algorithm based on singular value decomposition and slope-based embedding technique

In this work, we propose a robust watermarking algorithm for video copyright protection. The proposed algorithm is characterized by four key features. First, a robust feature obtained by singular value decomposition is selected to embed the watermark. Second, a novel slope-based embedding technique is developed to embed a 1-bit watermark into several successive blocks in the temporal direction, thus enhancing the robustness against global attacks. Third, an embedding location selection method is used to give priority to blocks with small variations that can enhance the visual quality of the watermarked video. Fourth, a temporal synchronization method is introduced to effectively withstand temporal synchronization attacks. The experimental results demonstrate that our scheme has good imperceptibility and is robust against various attacks, such as noise addition, filtering, gamma correction, lossy compression, scaling, frame dropping, frame insertion, and frame averaging. Furthermore, the watermark can be extracted using only some side information rather than the original video, which makes the scheme more practical.

Temporal Synchronization in Video Watermarking

One of the challenges for blind watermark detection is synchronization. Synchronization is the process of identifying the coordinates of an embedded watermark and is crucial in successful watermark detection. If the detector's input is watermarked but synchronization fails, then the embedded watermark will not be detected. In this paper, temporal synchronization for blind video watermark detection is examined by developing new models for watermark embedding and detection. The structure of the watermark, and specifically its key schedule, dramatically affects the ease of synchronization. The new embedder models the construction of the watermark by using a state machine key generator. The key generator can produce time-invariant, time-independent, and time-periodic key schedules as special cases. The watermark detector uses a queue and a state predictor to perform a search to establish and maintain temporal synchronization. These models are general and can be applied to many symmetric blind video watermarking techniques. It is shown that a watermark without temporal redundancy in its key schedule is vulnerable to attacks such as frame dropping and transposition. Using the models, a watermark more resilient against temporal synchronization attacks is designed by adding temporal redundancy in the watermark construction. Experimental results from an implementation of the models are presented.