Algorithms that I am aware of but have not found yet:
Chao Deng, Mengtao Shen, Jian Wang, "A fast algorithm for finding the Convex Hull of a Simple Polygon", Proceedings of the fourth International Conference on Computer-Aided Drafting, Design and Manufacturing Technology, Int. Acad. Publishers. Part vol.1, 1994 pp.183-6 vol.1. Beijing, China.
Wang Jiaye, Lie Dingyan, "A new linear algorithm for finding the convex hull of a 2D simple polygon", Chinese Journal of Computers, v.12 #1, p38, 1989.
Kong Xianshu, Cai Hongxue, "An algorithm for finding the convex hull of a simple polygon using active double line testing", Chinese Journal of Computers, vol.17, #8, Aug. 1994, pp.596-600, China.
Hopefully the Chinese Journal of Computers will reply to my email.