Qiuju Ji1, Peipeng Yu1, Zhihua Xia1, *
Journal on Big Data, Vol.2, No.1, pp. 33-51, 2020, DOI:10.32604/jbd.2020.01004
Abstract Aprivacy-preserving search model for JPEG images is proposed in paper, which
uses the bag-of-encrypted-words based on QDCT (Quaternion Discrete Cosine Transform)
encoding. The JPEG image is obtained by a series of steps such as DCT (Discrete Cosine
Transform) transformation, quantization, entropy coding, etc. In this paper, we firstly
transform the images from spatial domain into quaternion domain. By analyzing the
algebraic relationship between QDCT and DCT, a QDCT quantization table and QDTC
coding for color images are proposed. Then the compressed image data is encrypted after
the steps of block permutation, intra-block permutation, single table substitution and stream
cipher. At… More >
Login
Register
