An efficient watermarking algorithm for medical images

Multimedia Tools and Applications - Medical images exchanged over vulnerable networks are sensitive to modifications or tampering which could lead to misdiagnosis, risking the lives of the...     

Multi-level security of medical images based on encryption and watermarking for telemedicine applications

Multimedia Tools and Applications - In this paper, a robust and hybrid domain watermarking scheme is proposed for the security of medical images in telemedicine applications. The secret identity of...     

一种基于医学图像中感兴趣区域的数字水印算法

提出了一种基于医学图像中感兴趣区域(ROI)的盲检测水印算法,将包含重要病理信息的灰度图像作为数字水印,经置乱后在混沌序列的控制下嵌入到宿主小波域非感兴趣区域中。实验结果表明,该算法在保护医学ROI的同时提高了水印抗JPEG压缩的鲁棒性,并对篡改、几何剪切、滤波等均具有良好的鲁棒性和透明性,而且混沌序列增强了系统的安全性。     

空域彩色图像鲁棒零水印算法

针对传统变换域水印算法往往通过修改变换域系数来嵌入水印信号,影响图像不可感知性的问题,利用载体图像整体均值与分块均值之间大小关系的稳定性,提出一种新的空域彩色图像鲁棒零水印算法。算法直接在空域通过整体图像均值与分块均值之间的关系构造特征矩阵,之后将此特征矩阵与预处理后的水印信息进行异或运算构造零水印信息,预处理之后再注册到知识产权数据库里。提取水印信息时,通过投票策略得到最终提取的水印信息。大量的仿真实验结果表明,该算法对常规的信号处理攻击、行列平移、尺寸缩放和旋转等几何攻击具有较强的鲁棒性。与相似的鲁棒水印算法相比,对于大多数的攻击,该算法具有更优越的性能。     

YOLO-based ROI selection for joint encryption and compression of medical images with reconstruction through super-resolution network

Medical images contain significant patient information, and this confidential data should not be accessed without proper authorisation. Concurrently, due to the high redundancy of image data, compression is necessary to minimise image size and efficiently utilise network resources. This paper presents an effective joint encryption and compression method for medical images that prevent critical data leakage while reducing redundancy. Initially, a powerful real-time object detection method, You Only Look Once v7, is employed to accurately and swiftly detect the region of interest (ROI) within the medical images. Subsequently, a joint three-dimensional chaotic map and Huffman encoding are applied to secure medical images without compromising the compression ratio or increasing the time cost. Lastly, a super-resolution network is established at the receiver end to better reconstruct the ROI image for precise diagnostic purposes. The comprehensive experimental analysis demonstrates that our method delivers high levels of security, compression, and visual quality performance on standard datasets used in smart healthcare applications, at a minimum. Furthermore, our approach outperforms other competitive state-of-the-art schemes when compared. We hope this study will inspire further research within the healthcare community.     

一种用于版权保护的数字图像双水印算法

提出了一类抗压缩的鲁棒加半脆弱双水印算法。利用图像的纹理特性将原始图像分块，根据不同的嵌入强度将可见水印图像嵌入原始图像的频域中以显示所有权，然后在每个图像块的高频部分加入自嵌入不可见水印以认证图像。实验表明，此双水印系统能够达到标识、认证图像所有权的目的。     

Information hiding in medical images: a robust medical image watermarking system for E-healthcare

Electronic transmission of the medical images is one of the primary requirements in a typical Electronic-Healthcare (E-Healthcare) system. However this transmission could be liable to hackers who may modify the whole medical image or only a part of it during transit. To guarantee the integrity of a medical image, digital watermarking is being used. This paper presents two different watermarking algorithms for medical images in transform domain. In first technique, a digital watermark and Electronic Patients Record (EPR) have been embedded in both regions; Region of Interest (ROI) and Region of Non-Interest (RONI). In second technique, Region of Interest (ROI) is kept untouched for tele-diagnosis purpose and Region of Non-Interest (RONI) is used to hide the digital watermark and EPR. In either algorithm 8?×?8 block based Discrete Cosine Transform (DCT) has been used. In each 8?×?8 block two DCT coefficients are selected and their magnitudes are compared for embedding the watermark/EPR. The selected coefficients are modified by using a threshold for embedding bit a ‘0’ or bit ‘1’ of the watermark/EPR. The proposed techniques have been found robust not only to singular attacks but also to hybrid attacks. Comparison results viz-a - viz payload and robustness show that the proposed techniques perform better than some existing state of art techniques. As such the proposed algorithms could be useful for e-healthcare systems.     

一种基于混沌序列的多级图像加密方法

目前,利用混沌映射产生混沌序列的理论(已经成熟,但是混沌序列发生器总是在有限精度下实现,混沌迭代序列必将退化为周期序列。本论文在结合混沌技术和传统密码理论的基础上提出了一种基于混合混沌序列的图像加密方法,可以克服有效精度效应对混沌系统的影响,从而改善混沌序列特性。通过理论分析和仿真结果表明,这种混合混沌序列具有随机性好,实现容易,周期长等优点。此外,在较低实现精度下,能够得到周期大的序列,为在低成本下得到比较实用的序列密码提供了一种新的思路。     

Hybrid watermarking of medical images for ROI authentication and recovery

Medical image data require strict security, confidentiality and integrity. To achieve these stringent requirements, we propose a hybrid watermarking method which embeds a robust watermark in the region of non-interest (RONI) for achieving security and confidentiality, while integrity control is achieved by inserting a fragile watermark into the region of the interest (ROI). First the information to be modified in ROI is separated and is inserted into RONI, which later is used in recovery of the original ROI. Secondly, to avoid the underflow and overflow, a location map is generated for embedding the watermark block-wise by leaving the suspected blocks. This avoids the preprocessing step of histogram modification. The image visual quality, as well as tamper localization, is evaluated. We use weighted peak signal to noise ratio for measuring image quality of watermarked images. Experimental results show that the proposed method outperforms the existing hybrid watermarking techniques.     

Multi-layer security of medical data through watermarking and chaotic encryption for tele-health applications

In this paper, we present a robust and secure watermarking approach using transform domain techniques for tele-health applications. The patient report/identity is embedding into the host medical image for the purpose of authentication, annotation and identification. For better confidentiality, we apply the chaos based encryption algorithm on watermarked image in a less complex manner. Experimental results clearly indicated that the proposed technique is highly robust and sufficient secure for various forms of attacks without any significant distortions between watermarked and cover image. Further, the performance evaluation of our method is found better to existing state-of-the-art watermarking techniques under consideration. Furthermore, quality analysis of the watermarked image is estimated by subjective measure which is beneficial in quality driven healthcare industry.

     

A fuzzy based ROI selection for encryption and watermarking in medical image using DWT and SVD

Nowadays secure medical image watermarking had become a stringent task in telemedicine. This paper presents a novel medical image watermarking method by fuzzy based Region of Interest (ROI) selection and wavelet transformation approach to embed encrypted watermark. First, the source image will undergo fuzzification to determine the critical points through central and final intensity along the radial line for selecting region of interest (ROI). Second, watermark image is altered to time-frequency domain through wavelet decomposition where the sub-bands are swapped based on the magnitude value obtained through logistic mapping. In the each sub-band all the pixels get swapped, results in fully encrypted image which guarantees the watermark to a secure, reliable and an unbreakable form. In order to provide more robustness to watermark image, singular values are obtained for encrypted watermark image and key component is calculated for avoiding false positive error. Singular values of the source and watermark image are modified through key component. Experimental results reveal that the proposed algorithm attains high robustness and improved security to the watermarked image against various kinds of attacks.

     

A new algorithm for encryption/decryption for field applications

This paper proposes a novel scheme where the key k is generated as discrete logarithm of indices involving prime modulus p and any base value q. This base value q is an element of Z_p. The Discrete logarithm values are substituted for k in the encryption equation. During decryption the corresponding k’s are used to recover the plaintext. The sender embeds the p, q values along with the encrypted message and transmits it. This obviates the need for sending the full-length key along with the encrypted message. The proposed method ensures higher security in the transmission. The strength of the method lies in the difficulty of guessing p, q values, the entire key need not be transmitted and the full set of ASCII values of the Z₂₅₆ plane figure in the encryption process. The paper also discusses the difficulty of attempting brute force technique to discover p, q values. As an extension of this work, the authors are exploring the possibility of using the full set of UNICODE values instead of the restricted 8-bit ASCII set.     

A robust zero-watermarking algorithm for lossless copyright protection of medical images

Applied Intelligence - The continuous orthogonal moments of images have become a main tool used in zero-watermarking algorithms in recent years. However, there is a problem that should not be...     

Frequency-based nonrigid motion analysis: application to fourdimensional medical images

We present a method for nonrigid motion analysis in time sequences of volume images (4D data). In this method, nonrigid motion of the deforming object contour is dynamically approximated by a physically-based deformable surface. In order to reduce the number of parameters describing the deformation, we make use of a modal analysis which provides a spatial smoothing of the surface. The deformation spectrum, which outlines the main excited modes, can be efficiently used for deformation comparison. Fourier analysis on time signals of the main deformation spectrum components provides a temporal smoothing of the data. Thus a complex nonrigid deformation is described by only a few parameters: the main excited modes and the main Fourier harmonics. Therefore, 4D data can be analyzed in a very concise manner. The power and robustness of the approach is illustrated by various results on medical data. We believe that our method has important applications in automatic diagnosis of heart diseases and in motion compression     

A novel cascade encryption algorithm for digital images based on anti-synchronized fractional order dynamical systems

In this paper, an active control technique is employed for anti-synchronization between two identical fractional order reverse butterfly-shaped hyperchaotic systems. We have shown that the convergence rate of anti-synchronization error is very faster by increasing the value of an active controller gain. A new algorithm for image encryption and decryption is introduced and established by anti-synchronized fractional order dynamical systems. Experimental results show that the proposed encryption algorithm has high level security against various attacks. Further, it confirms that the new algorithm is more efficient compared to other existing algorithms.     

Mobile-cloud assisted framework for selective encryption of medical images with steganography for resource-constrained devices

In this paper, the problem of outsourcing the selective encryption of a medical image to cloud by resource-constrained devices such as smart phone is addressed, without revealing the cover image to cloud using steganography. In the proposed framework, the region of interest of the medical image is first detected using a visual saliency model. The detected important data is then embedded in a host image, producing a stego image which is outsourced to cloud for encryption. The cloud which has powerful resources, encrypts the image and sent back the encrypted marked image to the client. The client can then extract the selectively encrypted region of interest and can combine it with the region of non-interest to form a selectively encrypted image, which can be sent to medical specialists and healthcare centers. Experimental results and analysis validate the effectiveness of the proposed framework in terms of security, image quality, and computational complexity and verify its applicability in remote patient monitoring centers.     

A multimedia application for watermarking digital images based on a content based image retrieval technique

The current work is focused on the implementation of a robust multimedia application for watermarking digital images, which is based on an innovative spread spectrum analysis algorithm for watermark embedding and on a content-based image retrieval technique for watermark detection. The existing highly robust watermark algorithms are applying “detectable watermarks” for which a detection mechanism checks if the watermark exists or not (a Boolean decision) based on a watermarking key. The problem is that the detection of a watermark in a digital image library containing thousands of images means that the watermark detection algorithm is necessary to apply all the keys to the digital images. This application is non-efficient for very large image databases. On the other hand “readable” watermarks may prove weaker but easier to detect as only the detection mechanism is required. The proposed watermarking algorithm combine’s the advantages of both “detectable” and “readable” watermarks. The result is a fast and robust multimedia application which has the ability to cast readable multibit watermarks into digital images. The watermarking application is capable of hiding 2¹⁴ different keys into digital images and casting multiple zero-bit watermarks onto the same coefficient area while maintaining a sufficient level of robustness.     

Performance study of selective encryption in comparison to full encryption for still visual images

Securing digital images is becoming an important concern in today＇s information security due to the extensive use of secure images that are either transmitted over a network or stored on disks. Image encryption is the most effective way to fulfil confidentiality and protect the privacy of images. Nevertheless, owing to the large size and complex structure of digital images, the computational overhead and processing time needed to carry out full image encryption prove to be limiting factors that inhibit it of being used more heavily in real time. To solve this problem, many recent studies use the selective encryption approach to encrypt significant parts of images with a hope to reduce the eneryption overhead. However, it is necessary to realistically evaluate its performance compared to full encryption. In this paper, we study the performance and efficiency of image segmentation methods used in the selective encryption approach, such as edges and face detection methods, in determining the most important parts of visual images. Experiments were performed to analyse the computational results obtained by selective image encryption compared to full image encryption using symmetric encryption algorithms. Experiment results have proven that the selective encryption approach based on edge and face detection can significantly reduce the time of encrypting still visual images as compared to full encryption. Thus, this approach can be considered a good alternative in the implementation of real-time applications that require adequate security levels.     

A watermarking scheme for source authentication,ownership identification,tamper detection and restoration for color medical images

Multimedia Tools and Applications - This paper proposes a blind watermarking scheme that has ability of confidentiality, source authentication, ownership identification, integrity, tampering...