摘要
运用视觉密码方案对正方形图片加密,如果方案的像素扩展度m不是一个整数的平方,加密后图片会从正方形变为矩形,从而导致信息的丢失。本文在理论上证明了两种改进的外形比例不失真方案的关系,针对改进方案不能对某些图片边缘部分加密的问题,给出了先扩充图片再加密的方案,仿真实验表明,本方案是有效的。
If the pixel expansion m is not a square value, the secret image - a foursquare will be changed to a rectangle and consequently lead to the loss of information after performing the VCS technique. The relationship between two improved schemes, which solved the problem of aspect ratio variant is proved. At the same time a scheme of encrypting after increasing the secret image is provided to encrypt the edge of the image. Simulation results demonstrate that this scheme is effective.
出处
《计算机工程与设计》
CSCD
北大核心
2006年第11期1998-1999,2014,共3页
Computer Engineering and Design
关键词
视觉密码
视觉密码方案
外形比例
不失真
像素扩展度
visual cryptography
visual cryptography scheme
aspect ratio
invariant
pixel expansion
