Tamper detection and recovery for medical images using near-lossless information hiding technique.
Digital medical images are very easy to be modified for illegal purposes. For example, microcalcification in mammography is an important diagnostic clue, and it can be wiped off intentionally for insurance purposes or added intentionally into a normal mammography. In this paper, we proposed two methods to tamper detection and recovery for a medical image. A 1024 x 1024 x-ray mammogram was chosen to test the ability of tamper detection and recovery. At first, a medical image is divided into several blocks. For each block, an adaptive robust digital watermarking method combined with the modulo operation is used to hide both the authentication message and the recovery information. In the first method, each block is embedded with the authentication message and the recovery information of other blocks. Because the recovered block is too small and excessively compressed, the concept of region of interest (ROI) is introduced into the second method. If there are no tampered blocks, the original image can be obtained with only the stego image. When the ROI, such as microcalcification in mammography, is tampered with, an approximate image will be obtained from other blocks. From the experimental results, the proposed near-lossless method is proven to effectively detect a tampered medical image and recover the original ROI image. In this study, an adaptive robust digital watermarking method combined with the operation of modulo 256 was chosen to achieve information hiding and image authentication. With the proposal method, any random changes on the stego image will be detected in high probability.
Wu
Jeffery H K
JH
Department of Medical Imaging, Chang-Hua Christian Hospital, Changhua, Taiwan.
Chang
Ruey-Feng
RF
Chen
Chii-Jen
CJ
Wang
Ching-Lin
CL
Kuo
Ta-Hsun
TH
Moon
Woo Kyung
WK
Chen
Dar-Ren
DR
D000465:Algorithms; D016494:Computer Security / Q000592:standards*; D044962:Data Compression; D003952:Diagnostic Imaging / Q000592:standards*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008327:Mammography / Q000592:standards / Q000706:statistics & numerical data; D011356:Product Labeling; D011857:Radiographic Image Interpretation, Computer-Assisted; D012637:Security Measures