半色调可视加密算法的综合评价算法

已有半色调可视加密(HVC)算法的评价普遍采用正确解码率(CDR)或比特错误率(BER),未考虑信息隐藏对载体图像造成的干扰。提出一种半色调可视加密算法的综合评价算法,综合考虑信息隐藏对载体图像造成的干扰和提取秘密图像的错误率,选择平均每像素干扰值(ADPP)衡量信息隐藏对载体图像造成的干扰,为保证ADPP和BER数据范围的一致性,采用秘密图像结合隐藏阈值T计算最大平均干扰值(MAD),将ADPP和BER结合MAD和系数λ综合计算,得到半色调可视加密算法的综合干扰值(IDHVC)。该算法与已有综合评价算法相比,在运算量方面具有明显优势。通过实验验证,该算法可应用于灰度和彩色半色调可视加密算法的综合评价。

Integrated evaluation algorithm for halftone visual cryptography methods

Previous papers generally use CDR or BER to evaluate the performance of halftone visual cryptography(HVC)methods,but the distortion caused during data hiding process is not considered.This paper proposed an integrated evaluation algorithm for HVC methods which considered both the distortion caused by data hiding and BER of the extracted secret image.It chose ADPP to measure the distortion caused during data hiding process,and to ensure the consistency of ADPP and BER data ranges,the algorithm generated the max average distortion(MAD) by using the secret image and the threshold T,and then obtained integrated distortion of halftone visual cryptography(IDHVC) by compressive calculation of BER,ADPP,MAD and coefficient λ.Compared with the existing algorithms,the proposed method has obvious advantage in the amount of computation.Experimental results show the proposed algorithm can evaluate HVC in gray-scale and color halftone images.