Hierarchical Access Control and Content Protection in Medical Image Archives, Based on Inverse Pyramid Decomposition

In the paper is presented one new approach for management of medical databases with multi-layer access, based on the Inverse Pyramid Decomposition. This decomposition offers the ability for the development of interactive tools for multi-layer transfer of the processed visual information with consecutively quality improvement, selection of regions of interest, which to be directly accessed and represented with highest quality, and reliable content protection ensured by resistant and fragile watermarks embedding. The use of the Inverse Pyramid Decomposition permits insertion of multiple watermarks in the same file. The resistant watermarks are used to prove the documents authenticity, while the fragile watermarks hide preset Regions of Interest in the medical images which should be revealed by authorized users only, and prove any kind of editing of the protected visual content. The basic part of the database information which is at the low access level, could be used for various applications: disease history and treatment, statistics information, etc., and could support patients diagnostics, cure and telemedicine. The information, saved in the high access level(s) is accessible for authorized users only. Key-Words: Medical image databases, Management of image databases, Image content protection, Resistant watermark, Fragile watermark.