Siau-Chuin Liew

Reversible medical image watermarking for tamper detection and recovery

This research paper discussed the usage of watermarking in medical images to ensure the authenticity and integrity of the image and reviewed some watermarking schemes that had been developed. A design of a reversible tamper detection and recovery watermarking scheme was then proposed. The watermarking scheme uses a 640x480x8 bits ultrasound grayscale image as a sample. The concept of ROI (Region Of Interest) and RONI (Region Of Non Interest) were applied. Watermark embedded can be used to detect tampering and recovery of the image can be done. The watermark is also reversible.

A Review of Image Segmentation Methodologies in Medical Image

A precise segmentation of medical image is an important stage in contouring throughout radiotherapy preparation. Medical images are mostly used as radiographic techniques in diagnosis, clinical studies and treatment planning. This review paper defines the limitation and strength of each methods currently existing for the segmentation of medical images.

Tamper Localization and Lossless Recovery Watermarking Scheme

Tamper localization and recovery watermarking scheme can be used to protect the integrity and authenticity of medical images. In this paper, a simple tamper localization and recovery scheme that uses lossless compression was proposed. Lossy compression may also be applied when necessary. The watermarked image has the PSNR of 47.4 dB and the results show that tampering was successfully localized and tampered area was exactly recovered.

The usage of block average intensity in tamper localization for image watermarking

Tamper localization capable image watermarking scheme is able to detect the location of manipulated areas, and verify other areas as authentic. The usage of block average intensity in the tamper localization process is one of the popular techniques due to its easy implementation. The effectiveness of using average intensity for tamper localization had not been properly tested. Experiments were performed using a tamper localization watermarking scheme for medical image which is based on block average intensity. The results shows that the tamper localization process will fail in certain conditions and caused some tampering left undetected.

A survey of query expansion, query suggestion and query refinement techniques

The ineffectiveness of information retrieval systems often caused by the inaccurate use of keywords in a query. In order to solve the ineffectiveness problem in information retrieval systems, many solutions have been proposed over the years. The most common techniques are revolving around query modification techniques such as query expansion, query refinement, etc. Due to the high similarity in these query modification techniques, people are often confused about their differences. However, few existing survey papers compare their differences. Hence, in this paper, we first briefly discuss the basic technique of query expansion, query suggestion and query refinement, and then make a detailed comparison between these three techniques. We finally show the promising future research trend in the field of query modification.

A survey of medical image processing tools

A precise analysis of medical image is an important stage in the contouring phase throughout radiotherapy preparation. Medical images are mostly used as radiographic techniques in diagnosis, clinical studies and treatment planning. Medical image processing tool are also similarly as important. With a medical image processing tool, it is possible to speed up and enhance the operation of the analysis of the medical image. This paper describes medical image processing software tool which attempts to secure the same kind of programmability advantage for exploring applications of the pipelined processors. These tools simulate complete systems consisting of several of the proposed processing components, in a configuration described by a graphical schematic diagram. In this paper, fifteen different medical image processing tools will be compared in several aspects. The main objective of the comparison is to gather and analysis on the tool in order to recommend users of different operating systems on what type of medical image tools to be used when analysing different types of imaging. A result table was attached and discussed in the paper.

Watermarking of ultrasound medical images in teleradiology using compressed watermark

Abstract. The open accessibility of Internet-based medical images in teleradialogy face security threats due to the nonsecured communication media. This paper discusses the spatial domain watermarking of ultrasound medical images for content authentication, tamper detection, and lossless recovery. For this purpose, the image is divided into two main parts, the region of interest (ROI) and region of noninterest (RONI). The defined ROI and its hash value are combined as watermark, lossless compressed, and embedded into the RONI part of images at pixel’s least significant bits (LSBs). The watermark lossless compression and embedding at pixel’s LSBs preserve image diagnostic and perceptual qualities. Different lossless compression techniques including Lempel-Ziv-Welch (LZW) were tested for watermark compression. The performances of these techniques were compared based on more bit reduction and compression ratio. LZW was found better than others and used in tamper detection and recovery watermarking of medical images (TDARWMI) scheme development to be used for ROI authentication, tamper detection, localization, and lossless recovery. TDARWMI performance was compared and found to be better than other watermarking schemes.

Parallel digital watermarking process on ultrasound medical images in multicores environment

With the advancement of technology in communication network, it facilitated digital medical images transmitted to healthcare professionals via internal network or public network (e.g., Internet), but it also exposes the transmitted digital medical images to the security threats, such as images tampering or inserting false data in the images, which may cause an inaccurate diagnosis and treatment. Medical image distortion is not to be tolerated for diagnosis purposes; thus a digital watermarking on medical image is introduced. So far most of the watermarking research has been done on single frame medical image which is impractical in the real environment. In this paper, a digital watermarking on multiframes medical images is proposed. In order to speed up multiframes watermarking processing time, a parallel watermarking processing on medical images processing by utilizing multicores technology is introduced. An experiment result has shown that elapsed time on parallel watermarking processing is much shorter than sequential watermarking processing.

A Quick Glance at Digital Watermarking in Medical Images Technique Classification, Requirements, Attacks and Application of Tamper Localization

Digital watermarking is seen as a necessary and important field to be developed since the attacks and manipulations of digital documents and media are actively done. This paper surveys and reviews some basic theory about digital watermarking, such as the technique classification, requirements and possible attacks nowadays. Since all data in medical images are significantly important, the demand for the authentication is high. Therefore, this paper also focuses on a specific application of digital image watermarking for medical images which are tamper localization.

Experiment of Tamper Detection and Recovery Watermarking in PACS

Medical images such as x-rays, ultrasounds and MRI (Magnetic Resonance Imaging) plays an important role in helping the physicians to diagnose a disease or body conditions. These images can be tampered with existing image processing tools that is easily available. The usage of security measures such as watermarking can protect the integrity of the images. Numerous watermarking schemes with basic security functions and even tampered image recovery are available. But there is no research on the experimentation of watermarking in the operational environment that involves PACS (Picture Archiving and Communication Systems). This paper will focus on the experiment of selected watermarking scheme running in as imulated operation environment. The watermarked images will be tested to know its effectiveness by comparing its recovery rates.