Content protection and hierarchical access control in image databases

The paper presents a new technique for archiving and protecting content of visual medical information. A special format is developed based on a new Inverse Pyramid decomposition. The images are archived with the highest quality but their restoration is performed in accordance with the application. The image content is protected by inserting multiple fragile watermarks that can be extracted by authorized users only. The fragile watermark is inserted as additional decomposition layer and does not influence the image quality. This approach permits the creation of archiving systems with hierarchical access control.