Fig. 4
From: Periodic characteristics of the Josephus ring and its application in image scrambling
![Fig. 4](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs13638-018-1167-5/MediaObjects/13638_2018_1167_Fig4_HTML.png)
a Gray histograms of Lena. b Gray histograms of cipher Lena image
From: Periodic characteristics of the Josephus ring and its application in image scrambling
a Gray histograms of Lena. b Gray histograms of cipher Lena image