A study for watermark methods appropriate to medical images

The network system, including the picture archiving and communication syste m (PACS), is essential in hospital end medical imaging fields these days. M any medical images are accessed and processed on the web, as well as in PAC S. Therefore, any possible accidents caused by the illegal modification of medical images must be prevented. Digital image watermark techniques have b een proposed as a method to protect against illegal copying or modification of copyrighted material. Invisible signatures made by a digital image wate rmarking technique can be a solution to these problems. However, medical im ages have some different characteristics from normal digital images in that one must not corrupt the information contained in the original medical ima ges. In this study, we suggest modified watermark methods appropriate for m edical image processing and communication system that prevent clinically im portant data contained in original images from being corrupted. Copyright ( C) 2001 by W.B. Saunders Company.