3D Watermarking Research Articles

A robust 3D point cloud watermarking method based on the graph Fourier transform

Many modern applications make use of 3D modeling and / or reconstruction of complex objects, such as historical monuments and entire urban centers. One of the most common representations of these 3D models is by point clouds, which are a dense set of points irregularly organized in a 3D coordinate system. Usually, the acquisition methods are highly expensive due to the necessary equipment and size of these models. This factor motivates the proposal of watermarking techniques to guarantee the copyright protection as well as to detect illegal copies. This paper presents a non-blind watermarking method for 3D point clouds. The method is based on the graph Fourier transform, a recently introduced signal processing tool which has been applied to signals lying over arbitrarily irregular domains. Unlike other published works regarding point cloud watermarking, instead of inserting the bit sequence in the models’ spatial coordinates, in this work the bits are embedded in the color information attributed in each point of a cloud. Simulation results show high imperceptibility and robustness against several attacks, such as affine transformations, reordering, noise addition and cropping.

Fabricating QR codes on 3D objects using self-shadows

QR codes are essentially 2D matrix images that can be easily displayed physically on printed media or digitally on a screen. Their popularity is due to their fast readability and storage capacity. Applications vary widely from product tracking and identification to entertainment, advertising, encryption, and payment. In this work, we explore a novel representation of QR codes as 3D structures that are embedded on arbitrary shapes. Specifically, our method physically prints the 3D QR-code representation on a given region on the shape. Thus, in comparison to paper printed QR-codes, our 3D QR-codes are more resilient and reliable (e.g. harder to break and reproduce). 3D QR-codes are computed from their 2D counterpart as a carefully designed set of carved geometry modules on the surface which encode the black-and-white QR pattern. At the core of our method, we utilize self-shadows which are cast by 3D geometry modules on the surface to generate a correct black–white pattern with adequate contrast which can be easily decoded by standard QR readers. Our technique allows embedding 3D QR-codes on arbitrary objects with minimal modification of the shape and even on thin shell surfaces or highly curved ones. Our technique is robust to lighting environments and scanning angles and allows to easily decode 3D QR-codes with similarity to the 2D version. Finally, we demonstrate our technique feasibility by fabricating a wide range of examples using consumer-level 3D printers and common homogeneous materials. The feasibility and robust readability make 3D QR-codes a good candidate for embedding information on physical objects and open interesting directions in 3D manufacturing such as 3D printed objects ownership and 3D watermarking.

A Review on Anaglyph 3D Image and Video Watermarking

Thanks to the rapid growth of internet and the advanced development of 3D technology, 3D images and videos are proliferated over the networks. However, this causes several insecurity problems, and protecting this type of media has become a main challenge for many researchers. 3D watermarking is considered as an efficient solution for 3D data protection. In fact, it consists in embedding a secret key into a 3D content to protect it and in trying to extract it after any attack applied on marked 3D data. Anaglyph is the most popular and economical method among different 3D visualization methods. For this reason, it has become used for many 3D applications. Hence, 3D anaglyph watermarking presents an important research area, and several techniques have been proposed in order to protect this type of media. In this survey paper, the existing anaglyph 3D images and videos watermarking techniques are discussed. This discussion shows that the anaglyph video watermarking field is still not mature and new techniques should be proposed to improve the invisibility/robustness trade-off. In addition, based on the study of anaglyph generation methods, it is concluded that signature can be embedded during the generation stage.

Blind Robust 3D Mesh Watermarking Based on Mesh Saliency and Wavelet Transform for Copyright Protection

Three-dimensional models have been extensively used in several applications including computer-aided design (CAD), video games, medical imaging due to the processing capability improvement of computers, and the development of network bandwidth. Therefore, the necessity of implementing 3D mesh watermarking schemes aiming to protect copyright has increased considerably. In this paper, a blind robust 3D mesh watermarking method based on mesh saliency and wavelet transform for copyright protection is proposed. The watermark is inserted by quantifying the wavelet coefficients using quantization index modulation (QIM) according to the mesh saliency of the 3D semiregular mesh. The synchronizing primitive is the distance between the mesh center and salient points in the descending order. The experimental results show the high imperceptibility of the proposed scheme while ensuring a good robustness against a wide range of attacks including smoothing, additive noise, element reordering, similarity transformations, etc.

Review on Different Types of 3D Watermarking

In this paper, an attempt has been made to summarise the work done related to 3D watermarking in past years. Here, the different types of watermarking methodology for 3D models have been presented. Focus on the 3D watermarking is ensured, ranging from the earliest time till present, regarding their nature and robustness against various attacks.

A Watermarking Method for 3D Printing Based on Menger Curvature and K-Mean Clustering

Nowadays, 3D printing is widely used in many areas of life. This leads to 3D printing models often being used illegally without any payment to the original providers. Therefore, providers need a solution to identify and protect the copyright of 3D printing. This paper presents a novel watermarking method for the copyright protection of 3D printing based on the Menger facet curvature and K-mean clustering. The facets of the 3D printing model are classified into groups based on the value of Menger curvature and the K-mean clustering, and the mean Menger curvature of each group will then be computed for embedding the watermark data. The watermark data are embedded into the groups of facets by changing the mean Menger curvature of each group according to the bit of watermark data. In each group, we select a facet that has the Menger curvature closest to the changed mean Menger curvature, and we then transform the vertices of the selected facet according to the changed Menger curvature for the watermarked 3D printing model generation. Watermark data are extracted from 3D-printed objects, which are printed from the watermarked 3D printing models by the 3D printer. Experimental results after embedding the watermark verified that the proposed method is invisible and robust to geometric attacks such as rotation, scaling and translation. In experiments with an XYZ Printing Pro 3D printer and 3D scanner, the accuracy and performance of the proposed method was higher than the two previous methods in the 3D printing watermarking domain. The proposed method provides a better solution for the copyright protection of 3D printing.

3D anaglyph image watermarking approach

In this paper, a binary watermark is embedded and extracted using principal component analysis along with non-subsampled contourlet transform. Before the use of aforementioned techniques, the binary watermark is scrambled, for which we have used Arnold transform. This will by default add a level of security measures without a password. The approach as presented in the following paper is very efficient, novel, robust and blind. We have also considered the possibility of image processing attacks, hence we have employed non subsampled contourlet transform for the same. The scheme is tested on various images and we have come to a conclusion that this scheme is very performance oriented when compared to the existing watermarking techniques using 3D anaglyphic images.

A robust 3D mesh watermarking algorithm utilizing fuzzy C-Means clustering

A new robust 3D watermarking algorithm utilizing Fuzzy C-Means (FCM) clustering technique is presented. FCM clusters 3D mesh vertices into suitable and unsuitable choices to insert the watermark without occasioning visible deformation, and also it is tough for the attacker to determine places of the watermark insertion. Two watermarking processes are offered to insert the watermark into 3D mesh models. The first process utilizes topical statistical measurements like average and standard deviation in order to alter the values of vertices to secret watermark data into 3D mesh models, however, the second process utilizes a jumbled insertion planning to insert the watermark inside 3D mesh models utilizing the topical statistical measurements and altering 3D mesh vertices together. Simulation results show that the proposed algorithm is robust. The watermarked 3D mesh models are resistant to several attacks like similarity transforms, noise addition, cropping and mesh smoothing.

Steganalysis of 3D objects using statistics of local feature sets

3D steganalysis aims to identify subtle invisible changes produced in graphical objects through digital watermarking or steganography. Sets of statistical representations of 3D features, extracted from both cover and stego 3D mesh objects, are used as inputs into machine learning classifiers in order to decide whether any information was hidden in the given graphical object. The features proposed in this paper include those representing the local object curvature, vertex normals, the local geometry representation in the spherical coordinate system. The effectiveness of these features is tested in various combinations with other features used for 3D steganalysis. The relevance of each feature for 3D steganalysis is assessed using the Pearson correlation coefficient. Six different 3D watermarking and steganographic methods are used for creating the stego-objects used in the evaluation study.

Multimodal perception study on virtual 3D curved textures with vision and touch for interactive multimedia systems

Understanding the multimodal rendering of 3D shapes is becoming an important research topic as multimedia and virtual reality technologies are rapidly advancing. This study is aimed to investigate human perceptibility on the curvature and texture changes of 3D virtual surfaces across modalities, vision and touch. Our interest is to obtain perception data that can be used for 3D watermarking or data compression under a virtual reality environment providing multimodal interactions. For this study, we designed two psychophysical experiments to estimate curvature discrimination and texture detection thresholds on curvature surfaces over three conditions: vision only, touch only, and both vision and touch. The results show that touch is dominant at both discriminating curvature surfaces and detecting surface texture changes on a curved surface. In addition, the sensitivity of the both senses to detect texture changes linearly increases as a curvature value increases. Finally, the vision and touch senses compensate each other when both modalities are available at the same time. The thresholds from the present study can potentially be used as the upper limit for selecting watermark strengths or compression in order to ensure imperceptibility in a 3D visuohaptic multimedia systems.

Blind watermarking algorithm based on spiral scanning method and error-correcting codes

This work is a connecting link between the field of digital transmission and (3 Dimension) 3D watermarking. In fact, we propose in this paper a blind and robust watermarking algorithm for 3D multiresolution meshes. This data type, before being watermarked, is divided into GOTs (Group Of Triangles) using a spiral scanning method. At every instant, only one GOT is loaded into memory. It undergoes a wavelet transform. Embedding modifies the wavelet coefficients vector thus generated after being presented in a cylindrical coordinate system. After being watermarked, the current GOT will be released from memory to upload the next GOT. Information is coded using a turbo encoder to generate the codeword to be inserted. Once the entire mesh is scanned, the watermarked mesh is reconstructed. During extraction, the same steps are applied only on the watermarked mesh: our algorithm is then blind. Extracted data are decoded using Error-Correcting Code (turbocode) to correct errors that occurred. The results show that our algorithm preserves mesh quality even with a very large insertion rate while significantly minimizing used memory. Data extraction was done correctly despite the application of various attacks. Our algorithm is robust against most popular attacks such as similarity transformation, noise addition, smoothing, coordinate quantization, simplification and compression.

Robust and Blind 3D Mesh Watermarking in Spatial Domain Based on Faces Categorization and Sorting

In this paper, a 3D watermarking algorithm in spatial domain is presented with blind detection. In the proposed method, a negligible visual distortion is observed in host model. Initially, a preprocessing is applied on the 3D model to make it robust against geometric transformation attacks. Then, a number of triangle faces are determined as mark triangles using a novel systematic approach in which faces are categorized and sorted robustly. In order to enhance the capability of information retrieval by attacks, block watermarks are encoded using Reed-Solomon block error-correcting code before embedding into the mark triangles. Next, the encoded watermarks are embedded in spherical coordinates. The proposed method is robust against additive noise, mesh smoothing and quantization attacks. Also, it is stout next to geometric transformation, vertices and faces reordering attacks. Moreover, the proposed algorithm is designed so that it is robust against the cropping attack. Simulation results confirm that the watermarked models confront very low distortion if the control parameters are selected properly. Comparison with other methods demonstrates that the proposed method has good performance against the mesh smoothing attacks.

An Improved Security 3D Watermarking Method Using Computational Integral Imaging Cryptosystem

Robustness and security are difficult to be solved by conventional two-dimensional (2D) digital watermarking technology. In recent years, three-dimensional (3D) digital watermarking has become a new hotspot in optical information security. This paper presents a new improved security 3D digital watermarking method based on computational integrated imaging cryptosystem. Firstly, 3D digital watermarking is generated and encrypted by computational integral imaging cryptosystem that is implemented with smart pseudoscopic-to-orthoscopic conversion (SPOC) model. Secondly, discrete wavelet transform algorithm is applied to embed and extract the 3D digital watermarking. Finally, the extracted watermark is decrypted, and3D digital watermarking is displayed by integral imaging system. The feasibility and effectiveness of the proposed method is demonstrated by experiment. A primary implication of encrypted processing is that the majority of integral imaging cryptosystem will be encryption-in-the-loop applications, and the majority of system will improve the security and robustness of 3D digital watermarking. The new method is able to meet the requirements of robustness and security. Image quality and display quality achieve these criterions of the human visual model. The proposed method can be applied in the aspects of cloud computing and big data.

A 3D Steganalytic Algorithm and Steganalysis-Resistant Watermarking.

We propose a simple yet efficient steganalytic algorithm for watermarks embedded by two state-of-the-art 3D watermarking algorithms by Cho etal. The main observation is that while in a clean model the means/variances of Cho etal.'s normalized histogram bins are expected to follow a Gaussian distribution, in a marked model their distribution will be bimodal. The proposed algorithm estimates the number of bins through an exhaustive search and then the presence of a watermark is decided by a tailor made normality test or a t-test. We also propose a modification of Cho etal.'s watermarking algorithms with the watermark embedded by changing the histogram of the radial coordinates of the vertices. Rather than targeting a continuous statistics such as the mean or variance of the values in a bin, the proposed watermarking modifies a discrete statistic, which here is the height of the histogram bin, to achieve watermark embedding. Experimental results demonstrate that the modified algorithm offers not only better resistance against the steganalytic attack we developed, but also an improved robustness/capacity trade-off.

A robust and optimized 3D red-cyan anaglyph blind image watermarking in the DWT domain

A robust and optimized 3D red-cyan anaglyph blind image watermarking in the DWT domain

Euclidean Distance Distortion Based Robust and Blind Mesh Watermarking

The three-dimensional (3D) polygonal meshes are recently widely used in several domains, which necessitate the realistic visualization of the objects. Moreover, there is an urgent need to protect the 3D data properties for preventing unauthorized reproduction. The 3D digital watermarking technology is one of the best solutions to protect data from piracy during transmission through the internet. The current work proposed a novel robust watermarking scheme of polygonal meshes for copyright protection purposes. The proposed algorithm is based on the characteristics of the mesh geometry to embed a sequence of data bits into the object by slightly adjusting the vertex positions. Furthermore, the proposed method used a blind detection scheme. The watermarked model is perceptually indistinguishable from the original one and the embedded watermark is invariant to affine transformation. Through simulations, the quality of the watermarked object as well as the inserted watermark robustness against various types of attacks were tested and evaluated to prove the validity and the efficiency of our algorithm.

Two Kinds of Digital Video Watermarking Algorithm Implement and Compare

With the rapid development of multimedia technology, large amounts of digital information turn into easy storage and transmission, at the same time, copyright protection and authentication become a problem to be solved. Digital Video is composed of a series of continuous static images, because of its own characteristic, general image watermarking technology is difficult to direct extension to the video signal. In this paper, by using DCT transform and DWT transform, combined with the mean quantization algorithm, using three dimensional frequency domain transformation, introduces two kinds of transformation to the 3D video watermarking technology, utilize the quantitative test method to prove the existence of the watermark, and through the attacked experiments to verify the low complexity and well imperceptibility and robustness about the video watermarking algorithm.

3D image copyright protection based on cellular automata transform and direct smart pixel mapping

We propose a three-dimensional (3D) watermarking system with the direct smart pixel mapping algorithm to improve the resolution of the reconstructed 3D watermark plane images. The depth-converted elemental image array (EIA) is obtained through the computational pixel mapping method. In the watermark embedding process, the depth-converted EIA is first scrambled by using the Arnold transform, which is then embedded in the middle frequency of the cellular automata (CA) transform. Compared with conventional computational integral imaging reconstruction (CIIR) methods, this proposed scheme gives us a higher resolution of the reconstructed 3D plane images by using the quality-enhanced depth-converted EIA. The proposed method, which can obtain many transform planes for embedding watermark data, uses CA transforms with various gateway values. To prove the effectiveness of the proposed method, we present the results of our preliminary experiments.

Applying 3D Polygonal Mesh Watermarking for Transmission Security Protection through Sensor Networks

Although many research works have been carried out in the area of transmission 3D data through sensor networks, the security issue of transmission remains to be unsolved. It is important to develop systems for copyright protection and digital right management (DRM). In this paper, a blind watermarking algorithm is proposed to protect the transmission security of 3D polygonal meshes through sensor networks. Our method is based on selecting prominent feature vertices (prongs) on the mesh and then embedding the same watermark into their neighborhood regions. The embedding algorithm is based on modifying the distribution of vertex norms by using quadratic programming (QP). Decoding results are obtained by a majority voting scheme over neighborhood regions of these prongs. Assuming that cropping cannot remove all prongs, we can achieve robustness against the cropping attack both theoretically and experimentally. Experiments indicate that the proposed method is also robust against noise, smoothing, and mesh simplification. The proposed method has provided a solution for 3D polygonal watermarking which is potential to withstand a variety of attacks.

Optimized 3D Watermarking for Minimal Surface Distortion

This paper proposes a new approach to 3D watermarking by ensuring the optimal preservation of mesh surfaces. A new 3D surface preservation function metric is defined consisting of the distance of a vertex displaced by watermarking to the original surface, to the watermarked object surface as well as the actual vertex displacement. The proposed method is statistical, blind, and robust. Minimal surface distortion according to the proposed function metric is enforced during the statistical watermark embedding stage using Levenberg-Marquardt optimization method. A study of the watermark code crypto-security is provided for the proposed methodology. According to the experimental results, the proposed methodology has high robustness against the common mesh attacks while preserving the original object surface during watermarking.