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1.
Tamper localization and recovery watermarking scheme can be used to detect manipulation and recover tampered images. In this paper, a tamper localization and lossless recovery scheme that used region of interest (ROI) segmentation and multilevel authentication was proposed. The watermarked images had a high average peak signal-to-noise ratio of 48.7 dB and the results showed that tampering was successfully localized and tampered area was exactly recovered. The usage of ROI segmentation and multilevel authentication had significantly reduced the time taken by approximately 50 % for the tamper localization and recovery processing. 相似文献
2.
Medical imaging and information management systems require transmission of medical images over the Internet. Many image watermarking techniques have been proposed in recent years to ensure the integrity and authenticity of medical images transferred over insecure networks. In this work, we propose a new medical image watermarking technique to detect tampered regions on medical images with finer accuracy by authenticating 4 × 4 blocks and without restricting region of interest (ROI) size. The proposed method can mark a 4 × 4 pixel block if it has even one tampered pixel, while similar methods (which have no ROI size restriction) mark 8 × 8, 16 × 16, and 40 × 40 pixel blocks. Modified difference expansion (MDE) and least significant bit (LSB) embedding techniques are used together first in the literature by the method to embed authentication bits into corresponding blocks. The method uses a small 4 × 4 window to mark the tampered region. Experimental results show that the proposed method detects tampered regions on medical images with high accuracy and can be used by all medical image modalities. The results also indicate that the method has finer accuracy and no ROI size restriction compared to similar works reported in the literature. 相似文献
3.
Medical images exchanged over public networks require a methodology to provide confidentiality for the image, authenticity of the image ownership and source of origin, and image integrity verification. To provide these three security requirements, we propose in this paper a region-based algorithm based on multiple watermarking in the frequency and spatial domains. Confidentiality and authenticity are provided by embedding robust watermarks in the region-of-non-interest (RONI) of the image using a blind scheme in the discrete wavelet transform and singular value decomposition domain (DWT-SVD). On the other hand, integrity is provided by embedding local fragile watermarks in the region-of-interest (ROI) of the image using a reversible scheme in the spatial domain. The integrity provided by the proposed algorithm is implemented on a block-level of the partitioned-image, thus enabling localized detection of tampered regions. The algorithm was evaluated with respect to imperceptibility, robustness, capacity, and tamper localization capability, using MRI, Ultrasound, and X-ray gray-scale medical images. Performance results demonstrate the effectiveness of the proposed algorithm in providing the required security services for telemedicine applications. 相似文献
4.
Chun Kiat Tan Jason Changwei Ng Xiaotian Xu Chueh Loo Poh Yong Liang Guan Kenneth Sheah 《Journal of digital imaging》2011,24(3):528-540
Teleradiology applications and universal availability of patient records using web-based technology are rapidly gaining importance.
Consequently, digital medical image security has become an important issue when images and their pertinent patient information
are transmitted across public networks, such as the Internet. Health mandates such as the Health Insurance Portability and
Accountability Act require healthcare providers to adhere to security measures in order to protect sensitive patient information.
This paper presents a fully reversible, dual-layer watermarking scheme with tamper detection capability for medical images.
The scheme utilizes concepts of public-key cryptography and reversible data-hiding technique. The scheme was tested using
medical images in DICOM format. The results show that the scheme is able to ensure image authenticity and integrity, and to
locate tampered regions in the images. 相似文献
5.
The development of teleradiology brings the convenience of global medical record access along with the concerns over the security of medical images transmitted over the open network. With the prevailing adoption of three-dimensional (3-D) imaging modalities, it is vital to develop a security mechanism to provide large volumes of medical images with privacy and reliability. This paper presents the development of a new and improved method of implementing tamper detection and localization based on a fully reversible digital watermarking scheme for the protection of volumetric DICOM images. This tamper detection and localization method utilizes the 3-D property of volumetric data to achieve much faster processing time at both sender and receiver sides without compromising tamper localization accuracy. The performance of the proposed scheme was evaluated by using sample volumetric DICOM images. Results show that the scheme achieved on average about 65 % and 72 % reduction in watermarking and dewatermarking processing time, respectively. For cases where the images had been tampered, it is possible to detect and localize the tampered areas with improved localization resolution in the images using the scheme. 相似文献
6.
This paper presents a lossless watermarking scheme in the sense that the original image can be exactly recovered from the
watermarked one, with the purpose of verifying the integrity and authenticity of medical images. In addition, the scheme has
the capability of not introducing any embedding-induced distortion in the region of interest (ROI) of a medical image. Difference
expansion of adjacent pixel values is employed to embed several bits. A region of embedding, which is represented by a polygon,
is chosen intentionally to prevent introducing embedding distortion in the ROI. Only the vertex information of a polygon is
transmitted to the decoder for reconstructing the embedding region, which improves the embedding capacity considerably. The
digital signature of the whole image is embedded for verifying the integrity of the image. An identifier presented in electronic
patient record (EPR) is embedded for verifying the authenticity by simultaneously processing the watermarked image and the
EPR. Combining with fingerprint system, patient’s fingerprint information is embedded into several image slices and then extracted
for verifying the authenticity. 相似文献
7.
This article presents a lossless compression of volumetric medical images with the improved three-dimensional (3-D) set partitioning in hierarchical tree (SPIHT) algorithm that searches on asymmetric trees. The tree structure links wavelet coefficients produced by 3-D reversible integer wavelet transforms. Experiments show that the lossless compression with the improved 3-D SPIHT gives improvement about 42% on average over two-dimensional techniques and is superior to those of prior results of 3-D techniques. In addition, we can easily apply different numbers of decomposition between the transaxial and axial dimensions, which is a desirable function when the coding unit of a group of slices is limited in size. 相似文献
8.
Kuo-Hwa Chiang Kuang-Che Chang-Chien Ruey-Feng Chang Hsuan-Yen Yen 《Journal of digital imaging》2008,21(1):77-90
Over the past few years, the billows of the digital trends and the exploding growth of electronic networks, such as worldwide
web, global mobility networks, etc., have drastically changed our daily lifestyle. In view of the widespread applications
of digital images, medical images, which are produced by a wide variety of medical appliances, are stored in digital form
gradually. These digital images are very easy to be modified imperceptively by malicious intruders for illegal purposes. The
well-known adage that “seeing is believing” seems not always a changeless truth. Therefore, protecting images from being altered
becomes an important issue. Based on the lossless data-embedding techniques, two detection and restoration systems are proposed
to cope with forgery of medical images in this paper. One of them has the ability to recover the whole blocks of the image
and the other enables to recover only a particular region where a physician will be interested in, with a better visual quality.
Without the need of comparing with the original image, these systems have a great advantage of detecting and locating forged
parts of the image with high possibility. And then it can also restore the counterfeited parts. Furthermore, once an image
is announced authentic, the original image can be derived from the stego-image losslessly. The experimental results show that
the restored version of a tampered image in the first method is extremely close to the original one. As to the second method,
the region of interest selected by a physician can be recovered without any loss, when it is tampered. 相似文献
9.
Seyed Mojtaba Mousavi Alireza Naghsh S. A. R. Abu-Bakar 《Journal of digital imaging》2014,27(6):714-729
The ever-growing numbers of medical digital images and the need to share them among specialists and hospitals for better and more accurate diagnosis require that patients’ privacy be protected. As a result of this, there is a need for medical image watermarking (MIW). However, MIW needs to be performed with special care for two reasons. Firstly, the watermarking procedure cannot compromise the quality of the image. Secondly, confidential patient information embedded within the image should be flawlessly retrievable without risk of error after image decompressing. Despite extensive research undertaken in this area, there is still no method available to fulfill all the requirements of MIW. This paper aims to provide a useful survey on watermarking and offer a clear perspective for interested researchers by analyzing the strengths and weaknesses of different existing methods. 相似文献
10.
详细地介绍了一种基于随机回归识理论的医学图像无埚压缩方法,该方法的性能通过十幅X线胸部图像与DPCM方法进行了比较,实验结果表明:这种方法对实现医学图像的无损压缩是非常有效的。 相似文献
11.
Gran Badshah Siau-Chuin Liew Jasni Mohd Zain Mushtaq Ali 《Journal of digital imaging》2016,29(2):216-225
In teleradiology, image contents may be altered due to noisy communication channels and hacker manipulation. Medical image data is very sensitive and can not tolerate any illegal change. Illegally changed image-based analysis could result in wrong medical decision. Digital watermarking technique can be used to authenticate images and detect as well as recover illegal changes made to teleradiology images. Watermarking of medical images with heavy payload watermarks causes image perceptual degradation. The image perceptual degradation directly affects medical diagnosis. To maintain the image perceptual and diagnostic qualities standard during watermarking, the watermark should be lossless compressed. This paper focuses on watermarking of ultrasound medical images with Lempel-Ziv-Welch (LZW) lossless-compressed watermarks. The watermark lossless compression reduces watermark payload without data loss. In this research work, watermark is the combination of defined region of interest (ROI) and image watermarking secret key. The performance of the LZW compression technique was compared with other conventional compression methods based on compression ratio. LZW was found better and used for watermark lossless compression in ultrasound medical images watermarking. Tabulated results show the watermark bits reduction, image watermarking with effective tamper detection and lossless recovery. 相似文献
12.
The American Board of Imaging Informatics (ABII) was founded in 2005 by the Society of Imaging Informatics in Medicine (SIIM)
and the American Registry of Radiologic Technologists (ARRT). ABII’s mission is to enhance patient care, professionalism,
and competence in imaging informatics. This is accomplished primarily through the development and administration of a certification
examination. The creation of the exam has been an exercise in open community involvement with SIIM providing access to the
PACS community and ARRT providing skilled psychometric support to ensure a balanced and comprehensive examination. The process
to generate the exam required several years and the efforts of dozens of subject matter experts active who volunteered to
submit and validate questions for the examination. This article describes the organizational and statistical processes used
to generate test items, assemble test forms, set performance standards, and validate test scores. 相似文献
13.
目的:应用Java技术开发一个基于Web技术的操作简易、通用性强的医学图像发布环境。方法:采用Web服务器来查询和提取存储在DICOM服务器中的医学图像,客户端使用嵌有JavaApplet小程序的Web浏览器来访问Web服务器,完成客户端对服务器端医学图像的提取,JavaApplet小程序利用Web浏览器实现其图像操作。结果:我们使用Java技术开发一个基于Web技术的医学图像发布环境,完成了客户机通过Intemet对服务器端医学图像的读取操作,实现了异地专家的在线交流。结论:与大多数传统的PACS相比.基于Web技术的PACS系统易于安装和维护,与运行平台无关,可以高效的显示、处理医学图像,容易和使用Web技术构建的PACS系统整合。设置适当的安全防范措施,用户可以在医院外部实现对该系统的访问。Intemet技术的简易性和可扩展性使得该系统与传统PACS系统相比有着更大的优越性。 相似文献
14.
Teleradiology allows medical images to be transmitted over electronic networks for clinical interpretation and for improved healthcare access, delivery, and standards. Although such remote transmission of the images is raising various new and complex legal and ethical issues, including image retention and fraud, privacy, malpractice liability, etc., considerations of the security measures used in teleradiology remain unchanged. Addressing this problem naturally warrants investigations on the security measures for their relative functional limitations and for the scope of considering them further. In this paper, starting with various security and privacy standards, the security requirements of medical images as well as expected threats in teleradiology are reviewed. This will make it possible to determine the limitations of the conventional measures used against the expected threats. Furthermore, we thoroughly study the utilization of digital watermarking for teleradiology. Following the key attributes and roles of various watermarking parameters, justification for watermarking over conventional security measures is made in terms of their various objectives, properties, and requirements. We also outline the main objectives of medical image watermarking for teleradiology and provide recommendations on suitable watermarking techniques and their characterization. Finally, concluding remarks and directions for future research are presented. 相似文献
15.
Tzong-Jer Chen Ph.D. Keh-Shih Chuang Jen-Hao Chang Ya-Hui Shiao Chun-Chao Chuang 《Journal of digital imaging》2006,19(2):118-125
This study was undertaken to investigate a useful image blurring index. This work is based on our previously developed method,
the Moran peak ratio. Medical images are often deteriorated by noise or blurring. Image processing techniques are used to
eliminate these two factors. The denoising process may improve image visibility with a trade-off of edge blurring and may
introduce undesirable effects in an image. These effects also exist in images reconstructed using the lossy image compression
technique. Blurring and degradation in image quality increases with an increase in the lossy image compression ratio. Objective
image quality metrics [e.g., normalized mean square error (NMSE)] currently do not provide spatial information about image
blurring. In this article, the Moran peak ratio is proposed for quantitative measurement of blurring in medical images. We
show that the quantity of image blurring is dependent upon the ratio between the processed peak of Moran's Z histogram and the original image. The peak ratio of Moran's Z histogram can be used to quantify the degree of image blurring. This method produces better results than the standard gray
level distribution deviation. The proposed method can also be used to discern blurriness in an image using different image
compression algorithms. 相似文献
16.
提出了一种改进的灰度医学图像平滑滤波算法,此算法既有效地滤除了医学图像中的噪声,又能很好的保持了图像的边缘及细节,也克服了作者先前所提算法滤波后图像边缘出现毛刺的缺点。 相似文献
17.
医院在医疗设备采购过程中,医院与供应商之间的离不开诚信合作,打造医疗设备品牌离不开诚信采购的建设.诚信作为一种无形资产,是市场经济的黄金规则,是产品生存和发展的生命线.该文提出了对供应商采用的综合评分法与标准,评出优秀、合格与淘汰供应商. 相似文献
18.
This paper presents a novel algorithm to successfully achieve viable integrity and authenticity addition and verification
of n-frame DICOM medical images using cryptographic mechanisms. The aim of this work is the enhancement of DICOM security
measures, especially for multiframe images. Current approaches have limitations that should be properly addressed for improved
security. The algorithm proposed in this work uses data encryption to provide integrity and authenticity, along with digital
signature. Relevant header data and digital signature are used as inputs to cipher the image. Therefore, one can only retrieve
the original data if and only if the images and the inputs are correct. The encryption process itself is a cascading scheme,
where a frame is ciphered with data related to the previous frames, generating also additional data on image integrity and
authenticity. Decryption is similar to encryption, featuring also the standard security verification of the image. The implementation
was done in JAVA, and a performance evaluation was carried out comparing the speed of the algorithm with other existing approaches. The evaluation
showed a good performance of the algorithm, which is an encouraging result to use it in a real environment. 相似文献
19.
医学图像配准技术 总被引:4,自引:0,他引:4
申艳平 《中国医学物理学杂志》2013,30(1):3885-3889
目的:在医学影像领域,不同成像设备获取的信息不同,但互为补充,将这些信息融合在一起,为医生做出正确的诊断提供更多的依据,有助于提高医疗诊断和治疗水平。本文主要介绍医学图像配准技术的基本原理、方法、发展和临床应用。方法:大量参阅了该领域的有关文献,重点介绍了配准过程中的几何空间变换技术,分别综述了刚体变换和非刚体变换的主要方法,分析各种方法的优缺点,应用的适应范围,并对该领域的研究进行了展望。结果:在临床应用中刚体或近似刚体的配准只占很小的一部分,大多数情况下需要用非刚体变换来描述。目前,非刚体变换方法还不够成熟,各类方法都存在一定的局限性,在临床实际应用中,根据研究对象的差别建立合理的配准形变模型,选择合适的配准方法,优化计算方法,提高计算速度,进一步提高图像配准的准确性。结论:论文认为医学图像配准技术是医学图像处理研究领域中的热点方向之一,具有重要的临床应用价值。论文提出图像配准的精度直接影响后续的图像处理工作,如何提高配准精度仍是今后医学图像配准技术的研究方向。 相似文献
20.
超声医学图像滤波算法研究进展 总被引:8,自引:3,他引:5
主要讨论超声医学图像滤波算法的研究现状,几种主要的滤波方法(多方位滤波方法、自适应权值调节滤波方法、自适应窗口选取滤波方法、两步法等)面临的问题及发展的方向。作者通过实践,将有关算法应用于超声医学图像的处理,给出了处理结果,进行了几种算法的比较分析。 相似文献