Color-black-and-white visual cryptography scheme (CBW-VCS) is a methodology that utilizes colors to alleviate the pixel expansion problem. In a general $(k,n)$ CBW-VCS, when k and n become larger, the pixel expansion increases dramatically. In this paper, two constructions for constituting a $(k,n)$ threshold probabilistic CBW-VCS (PCBW-VCS) are introduced, where the generated color shares are non-expansible. The two proposed constructions are proven to be valid constructions which satisfy the security and contrast conditions. Theoretical analysis and sufficient experiments are demonstrated to shown the effectiveness and advantages of the proposed PCBW-VCSs.

彩色黑白视觉密码方案（CBW-VCS）是一种利用颜色缓解像素扩展问题的方法。总的来说$（ķ，ñ）$CBW-VCS，当k和n变大时，像素扩展急剧增加。在本文中，构成一个$（ķ，ñ）$引入了阈值概率CBW-VCS（PCBW-VCS），其中生成的颜色份额不可扩展。两种建议的构造都被证明是满足安全性和对比度条件的有效构造。理论分析和足够的实验证明了所提出的PCBW-VCS的有效性和优势。