(2,n) Visual Threshold Scheme Based on Permutation
Fang Li-guo, Bin Yu · Jisuanji gongcheng · 2007
Two parameters,pixel expansion and contrast,are very important in visual cryptography.It's very difficult to optimize both of them in theory.Based on permutation,a(2,n)scheme,which existence has been proved theoretically,is proposed.The method of construction has been carried out.Simulation results demonstrate that this scheme can balance performance between pixel expansion and contrast,i.e.,when the contrast is close to optimality,the pixel expansion is relatively minor.