A Modified Robust Image Hashing Using Fractional Fourier Transform for Image Retrieval

摘要

In order to improve the security and robustness of image retrieval, a novel image hashing algorithm based on fractional Fourier trans-form (FRFT) for content-based image retrieval (CBIR) application is proposed in this paper. By employing FRFT and normalized Hamming dis-tance, a robust hashing sequence is obtained by preprocessing, feature ex-tracting and post processing. The security of proposed algorithm is totally depended on the orders of FRFT which are saved as secret keys. For illus-tration, several benchmark images are utilized to show the feasibility of the image hashing algorithm. Experimental results show that the proposed scheme is robust against perceptually acceptable modifications to the image such as JPEG compression, mid-filtering, and rotation. Therefore, the scheme proposed in this paper is suitable for CBIR application.