Multiple-image encryption by two-step phase-shifting interferometry and spatial multiplexing of smooth compressed signal Project supported by the National Natural Science Foundation of China (Grant Nos. 61775121, 61307003, 61405122, and 11574311), Key R&D Program of Shandong Province, China (Grant No. 2018GGX101002), the Natural Science Foundation of Shandong Province, China (Grant No. R2016FM03), and the Fundamental Research Funds of Shandong University, China (Grant No. 2015GN031). |
(a)–(d) Four sparse images after 5-order Haar DWT; (e)–(h) the corresponding images after Arnold transform for (a)–(d). |