Light field image encryption based on spatial-angular characteristic

Abstract

The 4D light field (LF) can be sliced into the spatial domain and the angular domain. Different from traditional images, LF image can simultaneously capture the direction and position of light propagation. With the development of image encryption technology, the security protection of LF images need to be paid further attention. Existing LF image encryption methods only explore the spatial information of the LF image, but ignore the angular information of LF image. In this paper, we propose a novel scheme for LF image encryption based on the internal spatial-angular characteristic of LF image. Firstly, considering the characteristic representation of the LF, we use the discrete fractional Fourier transform (DFrFT) to process the spatial domain of the LF image. Afterwards, in the angular domain, we employ the difference in viewing angles extracted from multiple angles to compose an epipolar plane image (EPI). The ciphertext EPI obtained by Arnold transform is displayed as an angular domain ciphertext image after reverse reconstruction. Furthermore, weighted linear blending and Chen’s chaotic system are performed on the ciphertext images in the spatial and angular domains to obtain the final ciphertext image. Experimental results demonstrate the effectiveness and applicability of the proposed scheme for LF image encryption.