A Lightweight Spatio-Color Scrambled EtC System for JPEG XS Standard

In this paper, we propose a spatio-color scrambled Encryption-then-Compression (EtC) system for the JPEG XS standard to enhance security and invisibility. Previously, a line-based spatial scrambling scheme compatible with JPEG XS has been proposed for image encryption in EtC systems. This scheme enhances privacy protection by facilitating image encryption prior to compression. However, the visibility of color components remains unchanged from the original, while spatial components are scrambled. The proposed spatio-color scrambled EtC system for the JPEG XS standard introduces two color component scrambling techniques: RGB scrambling and YCbCr scrambling. Consequently, both security and invisibility performance are enhanced. Despite the introduction of color scrambling, the proposed EtC system maintains the same rate-distortion (RD) performance as the conventional spatial scrambling scheme. We demonstrate its efficacy through simulations using 8K ultra-high-definition images.