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.

/pdf/watermarking-techniques-used-in-medical-images-a-survey-2ntehh1yhk.pdf

Watermarking Techniques used in Medical Images: a Survey

Digital watermarking : applicability for developing trust in medical imaging workflows state of the art review

Transmission of medical images among remote places is a general practice in telemedicine. Medical images may be modified intentionally or accidentally as the transmission of these may take place through unsecure networks such as internet. Before making any diagnostic decisions, the medical practitioner has to verify the integrity of region of interest (ROI) in the received medical image in order to avoid wrong diagnosis. Watermarking can be used for checking the integrity of medical images. In this study, the authors propose a novel medical image watermarking method based on integer wavelet transform (IWT). This proposal verifies the integrity of ROI, precisely identifies tampered blocks inside ROI, provides robustness to the data embedded inside region of non-interest (RONI) and recovers original ROI. In the proposed method, the medical image is segmented into ROI and RONI regions. Hash value of ROI, recovery data of ROI and data of patient are embedded into RONI using IWT. Experimental results show that the proposed method provides robustness to the watermark data embedded inside RONI and accurately detects and localises tampered areas inside ROI and recovers the original ROI.

https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/iet-ipr.2014.0986

Robust medical image watermarking technique for accurate detection of tampers inside region of interest and recovering original region of interest

It is of great importance in telemedicine to protect authenticity and
integrity of medical images. They are mainly addressed by two technologies, which
are region of interest (ROI) lossless watermarking and reversible watermarking.
However, the former causes biases on diagnosis by distorting region of none interest
(RONI) and introduces security risks by segmenting image spatially for watermark
embedding. The latter fails to provide reliable recovery function for the tampered
areas when protecting image integrity. To address these issues, a novel robust
reversible watermarking scheme is proposed in this paper. In our scheme, a reversible
watermarking method is designed based on recursive dither modulation (RDM) to
avoid biases on diagnosis. In addition, RDM is combined with Slantlet transform and
singular value decomposition to provide a reliable solution for protecting image
authenticity. Moreover, ROI and RONI are divided for watermark generation to
design an effective recovery function under limited embedding capacity. Finally,
watermarks are embedded into whole medical images to avoid the risks caused by
segmenting image spatially. Experimental results demonstrate that our proposed
lossless scheme not only has remarkable imperceptibility and sufficient robustness,
but also provides reliable authentication, tamper detection, localization and recovery
functions, which outperforms existing schemes for protecting medical images

/pdf/a-novel-robust-reversible-watermarking-scheme-for-protecting-4p5837xktj.pdf

A novel robust reversible watermarking scheme for protecting authenticity and integrity of medical images

In telemedicine while transferring medical images tampers may be introduced. Before making any diagnostic decisions, the integrity of region of interest (ROI) of the received medical image must be verified to avoid misdiagnosis. In this paper, we propose a novel fragile block based medical image watermarking technique to avoid embedding distortion inside ROI, verify integrity of ROI, detect accurately the tampered blocks inside ROI, and recover the original ROI with zero loss. In this proposed method, the medical image is segmented into three sets of pixels: ROI pixels, region of noninterest (RONI) pixels, and border pixels. Then, authentication data and information of ROI are embedded in border pixels. Recovery data of ROI is embedded into RONI. Results of experiments conducted on a number of medical images reveal that the proposed method produces high quality watermarked medical images, identifies the presence of tampers inside ROI with 100% accuracy, and recovers the original ROI without any loss.

/pdf/medical-image-watermarking-technique-for-accurate-tamper-2pm71fx38t.pdf

Medical image watermarking technique for accurate tamper detection in ROI and exact recovery of ROI

Medical images have been used as one of the objects to diagnose the patient. A digitally formatted medical image is easier to be stored and distributed but also easier to be modified for illegal purposes. Digital image watermarking offers a solution to protect digital medical images. By embedding fragile authentication watermark, the watermarking system can detect and localize the tampered area of medical images. Moreover, by embedding the feature extraction in the form of average intensities of the image, an original image can be recovered from the tampered image. This paper will study and test a watermarking scheme using LSB Modification to perform tamper detection and recovery in the ROI. To make this watermarking scheme reversible, RLE is used to embed the original LSBs in the RONI to get higher embedding capacity. The experimental results show that this watermarking system can detect and localize tamper with up to 100% accuracy and perform image recovery up to 100% recovery rate until 20% of tempered area in ROI.

Medical image watermarking with tamper detection and recovery using reversible watermarking with LSB modification and run length encoding (RLE) compression

Febri Puguh Permana

Papers

Medical image watermarking with tamper detection and recovery using reversible watermarking with LSB modification and run length encoding (RLE) compression