A Robust Algorithm of Encrypted Medical Image Retrieval Based on 3D DFT

摘要

Cloud computing platform is not a fully trusted third party, which may leak the patient's personal information when we store medical image, so we need to encrypt medical image. Meanwhile, in order to help doctors who can find out historical cases from the medical image database which are similar to the current diagnostic image to make more accurate diagnosis and treatment, this paper proposes an robust algorithm based on 3D DFT for encrypted medical image retrieval. At first, we extract feature vector of 3D encrypted image and establish features vector database. Next, the NC (Normalized Cross Correlation Coefficient) between the feature vector of query medical image and each one in the features vector database is computed automatically. Finally, the corresponding encrypted image with the highest NC value is returned. The results show that this algorithm has strong robustness against common attacks and geometric attacks.