Accuracy Of Tamper Localization Research Articles

A blind recovery technique with integer wavelet transforms in image watermarking

The development of internet technology has simplified the sharing and modification of digital image information. The aim of this study is to propose a new blind recovery technique based on integer wavelets transform (BRIWT) by utilizing their image content. The LSB adjustment technique on the integer wavelet transform is used to embed recovery data into the two least significant bits (LSB) of the image content. Authentication bits are embedded into the current locations of the LSB of the image content, while the recovery information is embedded into different block locations based on the proposed block mapping. The embedded recovery data is securely placed at random locations within the two LSBs using a secret key. A three-layer embedding of authentication bits is used to validate the integrity of the image contents, achieving high precision and accuracy. Tamper localization accuracy is employed to identify recovery bits from the image content. This research also investigates the image inpainting method to enhance recovery from tampered images. The proposed image inpainting is performed by identifying non-tampered pixels in the surrounding tamper localization. The results demonstrate that the proposed scheme can produce highly watermarked images with imperceptibility, with an average SSIM value of 0.9978 and a PSNR value of 46.20 dB. The proposed scheme significantly improves the accuracy of tamper localization, with a precision of 0.9943 and an accuracy of 0.9971. The proposed recovery technique using integer wavelet transforms achieves high-quality blind recovery with an SSIM value of 0.9934 under a tampering rate of 10%. The findings of this study reveal that the proposed scheme improves the quality of blind recovery by 14.2 % under a tampering rate of 80 %.

A secure pixel level self-recovery scheme for digital images

This paper presents a secure image authentication scheme for tamper localization and recovery at pixel level. The proposed scheme encrypts the watermark comprising tamper localization code and self-recovery code using chaotic sequence to ensure security. This scheme uses pixel to block conversion technique for ensuring lossless recovery of the original image from an untampered watermarked image. For enhancing the localization accuracy, a multilevel tamper localization strategy is used. The experimental results show that the proposed scheme generates watermarked images with minimal information loss and can withstand copy-move, image splicing, content removal, vector quantization, collage and content only attacks. This scheme has better security, better tamper localization accuracy and better recovered image quality under extensive tampering and takes less computation time in comparison to the state-of-the-art schemes.

Fragile Watermarking for Tamper Localization and Self-Recovery Based on AMBTC and VQ

Digital images have unique features that include being both easily transmittable over the Internet and being easy to tamper. With the advancement of digital processing techniques and an increasing number of valuable digital images being transmitted via the Internet, image authentication has been made more crucial than ever. In this paper, we present an image authentication scheme with tamper localization and self-recovery using fragile watermarking. We embed the fragile watermarks consisting of the authentication code and the recovery information onto the image to verify its integrity. The proposed fragile watermarking scheme can authenticate the image without accessing the original image, localizing the modifications as well as verifying the integrity, and even reconstructing the tampered regions. We use an AMBTC compressed code as the authentication code to minimize the distortion introduced by embedding. To reduce the blocking effect that occurs in the reconstructed image, a VQ compressed code is applied instead of the average intensity as the recovery information. Several representative test images and 200 different test images were randomly selected from BOWS to examine the performance of the proposed scheme. Experimental results confirm that the proposed scheme can effectively resist a cutting attack and a copy-paste attack while retaining the high accuracy of tamper localization. The average TPR and average FTP rate were around 97% and 0.12%, respectively, while maintaining the image quality of the watermarked image and restoring the image at up to 48 dB and 39.28 dB, respectively.

Fragile watermarking scheme for tamper localization in images using logistic map and singular value decomposition

This paper presents a fragile watermarking scheme for tamper localization using Singular Value Decomposition (SVD) and logistic map. The proposed scheme divides the image into blocks of size 2 × 2 pixels and generates an 8-bit watermark from each block. The watermark is computed by permuting the six Most Significant Bits (MSBs) of each pixel in the block using the logistic map, followed by SVD. To secure, the watermark thus generated is further encrypted using the logistic map. This encrypted watermark is embedded into 2 Least Significant Bits (LSBs) of each pixel to enable tamper detection and localization. The experimental results demonstrate that the proposed scheme can precisely locate tampered regions under copy-paste, content removal, text addition, noise addition, vector quantization, collage, content only, and constant feature attacks. Tamper localization accuracy is better or comparable to the state-of-the-art tamper localization algorithms.

A survey on fragile watermarking based image authentication schemes

Ensuring the image content authentication is a necessity need when images are used as supporting evidence in critical applications such as law enforcement, medical diagnosis, news reporting, and forensic investigation. Fragile watermarking is an effective solution for ensuring image content authentication. This paper presents a survey on fragile watermarking schemes for tamper localization and self-recovery. The characteristics and general framework are included to get an overview of these schemes. A brief review and comparison of various fragile watermarking schemes along with their merits and limitations are also given. The observations drawn from the comparative study are included to aid further research in this area. In addition to this, experimental evaluation of state-of-the-art tamper localization and self-recovery schemes in terms of watermarked image quality, tamper localization accuracy, and recovery capability is carried out.

Semi-fragile self-recovery watermarking scheme based on data representation through combination

The widely available multimedia editing tools and their large reconstruction capabilities make digital multimedia content more sensitive to malicious tampering and manipulations. Therefore, ensuring digital image integrity has become a crucial issue. Watermarking became a popular technique for image authentication. The goal of this paper is to propose a new semi-fragile watermarking scheme for image authentication, localization, and recovery, by using two different watermarks jointly. The embedded information watermark for content recovery is computed from discrete wavelet transform (DWT) approximation coefficients of second level decomposition of the original image and compressed by using Data Representation through Combination (DRC) in order to reduce watermark payload. On another hand, authentication watermark used for both authentication and localization of image tampering is computed by using the block-based watermarking algorithm. Three pseudo-random maps are generated in order to improve the security of the proposed scheme against local attack. Both watermarks are embedded into approximation sub-band of the first wavelet decomposition. Experimental results show that our proposed approach has not only an extremely high accuracy of tampering localization but also a relatively very high recovery rate. Besides, the scheme is able to detect perfectly the difference between malicious attacks and non-malicious attacks such as JPEG compression.

An Effective Authentication Algorithm for Polygonal Models with High Embedding Capacity

Fragile watermarking algorithms for 3D models has attracted extensive research attention in recent years. Although many literatures have proposed lots of solutions on this issue, low embedding capacity and inaccurate located tampered region are still presented. Higher embedding capacity can reduce the probability of false alarms for authentication, while accurate tamper localization can detect all the modified vertices with fewer unaltered ones. This study proposes three strategies to enhance the embedding capacity and the detection accuracy of our previous algorithm. First, the modified message-digit substitution table can increase the embedding capacity by 11.5%. Second, the modified embedding ratio generation method can be integrated to raise the embedding capacity by about 47.74%. Finally, the strategy adopting a reduced number of reference vertices for authentication code generation accompanying the above two ones improves the embedding capacity up to 123.74%. Extensive experiments show that the proposed algorithm can achieve superior performance in terms of embedding capacity and tamper localization accuracy. Further, the model distortion between the original and the marked ones is small.

Image self-recovery with watermark self-embedding

In this paper, an effective image authentication method for image tamper detection and self-recovery is proposed. We embed the fragile watermark of one block which consists of authentication data and recovery data into the other block according to the embedding sequence generated by chaotic map. To reduce the smoothing blocking effect of recovered images, we use the wavelet transform rather than the average as recovery data to enhance the image contrast. In the tamper detection process, a hierarchical tamper detection strategy is adopted to achieve high tamper detection accuracy. To solve tampering coincidence problem, a two-level self-recovery scheme is proposed by considering the 3×3 block-neighborhood. Simulation results demonstrate that the proposed scheme can effectively resist collage attack and constant-average attack, while sustaining superior accuracy of tamper localization. Furthermore, the results show that the tampered images can be effectively self-recovered with a high visual contrast.

A Novel Hybrid Information Security Scheme for 2D Vector Map

Information hiding is an essential research topic in the theory of hybrid information security. 2D vector map contains a wealth of hybrid information, which requires verification of authenticity and integrity. This paper proposes a novel hybrid information security scheme for 2D vector map. The features in vector map are first divided into disjoint groups to ensure the accuracy of tamper localization. In order to locate the batch features deletion attack, we design a feature group correlation technique based on vertex insertion. And a fragile watermark is generated by combining with polar coordinate transformation and hash function, which is robust to resist rotation, uniform scaling and translation (RST) operations. And we embed the watermark with an RST invariant watermarking method. We construct two datasets for experimentation and the results compared with previous methods indicate that the proposed scheme has good invisibility and high tampering localization accuracy on the feature addition and deletion attack.

Secure and Robust Fragile Watermarking Scheme for Medical Images

Due to the advances in computer-based communication and health services over the past decade, the need for image security becomes urgent to address the requirements of both safety and non-safety in medical applications. This paper proposes a new fragile watermarking-based scheme for image authentication and self-recovery for medical applications. The proposed scheme locates image tampering as well as recovers the original image. A host image is broken into $4\times 4$ blocks and singular value decomposition (SVD) is applied by inserting the traces of block wise SVD into the least significant bit of the image pixels to figure out the transformation in the original image. Two authentication bits namely block authentication and self-recovery bits are used to survive the vector quantization attack. The insertion of self-recovery bits is determined with Arnold transformation, which recovers the original image even after a high tampering rate. SVD-based watermarking information improves the image authentication and provides a way to detect different attacked area of the watermarked image. The proposed scheme is tested against different types of attacks such as text removal attack, text insertion attack, and copy and paste attack. Compared with the state-of-the art methods, the proposed scheme greatly improves both tamper localization accuracy and the peak signal to noise ratio of self-recovered image.

Block Truncation Coding based effective watermarking scheme for image authentication with recovery capability

Due to the advancement of photo-editing software, powerful computers and high resolution capturing devices, it has become tough to prevent the digital image from tampering. So, in these days just by looking a digital image we cannot say whether it is a genuine or not. This is why digital image authentication, as well as restoration, has become the essential issues, especially when it is utilized in medical science, evidence of court, and forensic science. This paper proposes an effective self-embedding fragile watermarking technique for the digital image authentication as well as recovery. The watermark is generated by quantization, and block truncation coding (BTC) of each 2 × 2 non-overlapping block and embedded in three least significant bits (LSBs) of the corresponding mapped block. The recovery bits are derived from most significant bits (MSBs) of the host image, and the authentication bits are derived from recovery bits, the spatial location of pixels and watermark keys. Even if tempering rate is 50%, the reconstruction of tampered image is achieved with high peak signal-to-noise ratio (PSNR) and normalized correlation coefficient (NCC). The experimental results demonstrate that the proposed scheme not only outperforms high-quality recovery fidelity but also negotiate the blocking artifacts additionally it improves the accuracy of tamper localization due to the use of very small size blocks.

Tamper recovery algorithm for digital speech signal based on DWT and DCT

It is a challenging work to design tamper recovery schemes for digital speech signal. Briefly, there are two problems need to be solved. One is that the signals used to tamper recovery are difficult to generate and embed, and the second is that it's hard to tamper location precisely for attacked speech signal. In this paper, compression and reconstruction method based on discrete wavelet transform (DWT) and discrete cosine transform (DCT) is given, to obtain the compressed signals used to tamper recovery. And then frame number and compressed signals are embedded based on block-based method. Attacked signal can be located by frame number, and compressed signals are extracted and used to reconstruct the attacked signal. Theory analysis and experimental results indicate that the scheme proposed not only improves the accuracy of tamper localization, but also can reconstruct the attacked signals.

Effective self-embedding watermarking scheme for image tampered detection and localization with recovery capability

This paper presents a Discrete Cosine Transformation (DCT) based effective self-recoverable fragile watermarking scheme. For each 2×2 non-overlapping block, two authentication bits, and ten recovery bits are generated from the five most significant bits (MSBs) of pixels. Authentication bits are embedded in the three least significant bits (LSBs) of the block itself while recovery bits are embedded in the three LSBs of the corresponding mapped block. The proposed watermarking scheme is also effective because the authentication of each block is based on two levels hierarchical tampered detection mechanisms. So the detection of tampered block can be ensured with high probability. The experimental results demonstrate that the proposed scheme not only outperforms high-quality restoration effectively, but also removes the blocking artifacts and improves the accuracy of tamper localization due to the use of very small size blocks, smoothing function and two levels tampering detection mechanisms.

Reversible Fragile Watermarking for Locating Tampered Polylines/Polygons in 2D Vector Maps

For 2D vector maps, obtaining high tamper localization accuracy without requiring extra space is a technically challenging problem. Using an adaptive group division approach and an improved reversible data hiding approach, the author proposes a reversible fragile watermarking method for locating tampered Polylines/Polygons in 2D vector maps. In particular, the author adaptively divide the features of the vector map into groups according to a predefined threshold, calculate an authentication watermark for each group, embed the watermark using the improved reversible data hiding approach, and hide the mark of each feature into the feature itself. Since the adaptive group division method and the improved reversible data hiding method are combined in an attempt to make full use of the watermark embedding space, superior tamper localization accuracy and original content recovery can be ensured. Besides, no extra space is required by hiding the mark of each feature. Experimental results have been provided to demonstrate the effectiveness of our method.

DCT based efficient fragile watermarking scheme for image authentication and restoration

Due to rapid development of Internet and computer technology, image authentication and restoration are very essential, especially when it is utilized in forensic science, medical imaging and evidence of court. A quantization and Discrete Cosine Transform(DCT) based self-embedding fragile watermarking scheme with effective image authentication and restoration quality is proposed in this paper. In this scheme, the cover image is divided in size of 2×2 non-overlapping blocks. For each block twelve bits watermark are generated from the five most significant bits (MSBs) of each pixel and are embedded into the three least significant bits (LSBs) of the pixels corresponding to the mapped block. The proposed scheme uses two levels encoding for content restoration bits generation. The restoration is achievable with high PSNR and NCC up to 50 % tampering rate. The experimental results demonstrate that the proposed scheme not only outperforms high quality restoration effectively, but also removes the blocking artifacts and improves the accuracy of tamper localization due to use of very small size blocks.

Two Fragile Encryption-Watermarking Combined Schemes for Image Authentication with Tamper Detection and Localization

paper presents two fragile watermarking schemes for digital image authentication with tamper detection and localization. We combine a proposed chaos-based encryption algorithm with the two schemes in order to improve the security, tamper detection sensitivity and tamper localization accuracy of the two schemes. The first proposed fragile watermarking scheme can be classified as a block-based scheme that divides the cover image into non-overlapping 4×4 blocks. We generate an 8-bit authentication watermark for each cover image block based on the block contents and then we use the proposed chaos-based encryption algorithm to encrypt this watermark. These encrypted 8-bit watermark are then embedded into the least significant bits (LSBs) of the highest intensity eight pixels of the block. On the other hand, the second proposed watermarking scheme can be classified as a wavelet-based scheme which uses an external secret watermark. This watermark is encrypted using the proposed chaos-based encryption algorithm. We decompose the cover image using Discrete Wavelet Transform (DWT) and then we use the encrypted watermark to update the approximation coefficients (LL sub-band) of the image. Various experimental tests are carried out to evaluate the performance of the two schemes. Experimental results demonstrate that the two proposed schemes can detect and localize tampering attacks accurately. The two schemes also achieve high degree of imperceptibility performance. Compared to some fragile watermarking schemes, our proposed schemes are more secure and efficient.

Block-based Reversible Fragile Watermarking for 2D Vector Map Authentication

In this paper, the authors propose a block-based reversible watermarking method for 2D vector map authentication. In the scheme, they divide the features of a vector map into different categories of blocks, calculate an authentication watermark for each block, and embed the watermarks of different blocks using a reversible watermarking method based on virtual coordinates and a fragile watermarking algorithm based on concentric circles. While the block division ensures superior accuracy of tamper localization, the two watermarking methods provide recovery of the original content. Experimental results show that the proposed scheme has good invisibility, reversibility and computational complexity, and can accurately locate malicious attacks such as vertex modification/addition/deletion and feature modification/addition/deletion.

RST Invariant Fragile Watermarking for 2D Vector Map Authentication

D vector maps are very important data in geographical information systems (GISs). It is considered to be content for which verification of integrity and authentication are urgently required. Using a marking technique and a rotation, scaling and translation (RST) invariant watermark generation method, we propose a scheme that detects and locates malicious attacks with high accuracy while providing the RST invariance property. In particular, we propose setting a unique mark on each feature, calculating the authentication watermark for each spatial feature group by folding the hash results of the differences of the log-radiuses, and embedding the watermark using a RST invariant watermarking method. While the watermark ensures both the sensitivity to malicious manipulations and the RST invariance property, the mark of each feature provides superior accuracy of tamper localization. Moreover, this algorithm is immune to feature rearrangement and vertex reversing operations. Theoretical analysis and experimental results are provided to demonstrate the effectiveness of our method.

A High-Quality Image Authentication Scheme for AMBTC-compressed Images

In this paper, we present a high-quality image authentication scheme based on absolute moment block truncation coding. In the proposed scheme, we use the parity of the bitmap (BM) to generate the authentication code for each compressed image block. Data hiding is used to authenticate whether the content has been altered or not. For image authentication, we embed the authentication code to quantization levels of each image block compressed by absolute moment block truncation coding (AMBTC) which will be altered when the host image is manipulated. The embedding position is generated by a pseudo-random number generator for security concerned. Besides, to improve the detection ability we use a hierarchical structure to ensure the accuracy of tamper localization. A watermarked image can be precisely inspected whether it has been tampered intentionally or incautiously by checking the extracted watermark. Experimental results demonstrated that the proposed scheme achieved high-quality embedded images and good detection accuracy, with stable performance and high expansibility. Performance comparisons with other block-based data hiding schemes are provided to demonstrate the superiority of the proposed scheme.

New fragile watermarking method for stereo image authentication with localization and recovery

To address issues of image authenticity verification and integrity protection, a fragile watermarking method for stereo image authentication is proposed with stereo matching technique. According to stereo matching of left and right images, non-overlapping blocks of left image are classified into non-matchable and matchable ones. Right image blocks and non-matchable blocks of left image are categorized into smooth, texture and complex blocks considering their roughness. Then, the corresponding alterable-length watermark is computed based on the results of block classification, and the destroyed blocks are recovered by using the corresponding alterable-length watermark. Besides, matchable tampered blocks of left image are recovered with the matched contents in right image. A detection technique with the part of alterable-length watermark is used to increase accuracy of tamper localization at the receiver. The disparity can be used to recover the tampered matchable block. Therefore, the quality of watermarked images is improved because of low embedding capacity. Additionally, the alterable-capacity watermark provides suitable information for smoother images with fewer bits and we obtain high quality restoration. Experimental results show that the proposed method can not only localize the tampered regions precisely but also recover the tampered regions with higher quality compared with the state-of-the-art methods.