XOR-based visual cryptography scheme (XVCS) is a promising branch of VCS since superior visual quality of recovered secret image is provided. To assist the shadow management, meaningful shadow is preferred. However, existing extended XVCSs (EXVCSs) that generate meaningful shadows are confined to the $(n,n)$ threshold. They are not practical for real-world applications. In this paper, we introduce EXVCS for $(k,n)$ threshold and general access structure (GAS) by using integer linear program (ILP) technique. First of all, an approach for implementing the $(k,n)$-XVCS is given. We associate the $(k,n)$-XVCS with a minimizing problem, where the constraints in this problem are derived from the contrast and security conditions in $(k,n)$-XVCS. The ILP technique is adopted to solve this problem for obtaining the best solutions for constructing the base matrices for $(k,n)$-XVCS. Further, the construction is extended to $(k,n)$-EXVCS, in which the shadows with meaningful contents are constructed. To realize complicated sharing strategies, a construction of EXVCS for GAS is described as well. The base matrices for XVCS and EXVCS are demonstrated, as well as the pixel expansion and contrast. Comparisons among related methods are illustrated to show the advantages of the proposed schemes.

基于XOR的视觉密码方案（XVCS）是VCS的一个有前途的分支，因为它提供了恢复的秘密图像的卓越视觉质量。为了协助阴影管理，首选有意义的阴影。但是，现有的生成有意义的阴影的扩展XVCS（EXVCS）仅限于$（ñ，ñ）$临界点。它们不适用于实际应用。在本文中，我们将EXVCS引入$（ķ，ñ）$使用整数线性程序（ILP）技术的阈值和通用访问结构（GAS）。首先，一种实现$（ķ，ñ）$-XVCS已给出。我们关联$（ķ，ñ）$-XVCS，具有最小化问题，其中此问题的约束来自于对比和安全条件 $（ķ，ñ）$-XVCS。采用ILP技术可以解决该问题，从而获得构建基本矩阵的最佳解决方案。$（ķ，ñ）$-XVCS。此外，该结构扩展到$（ķ，ñ）$-EXVCS，在其中构造具有有意义内容的阴影。为了实现复杂的共享策略，还描述了用于GAS的EXVCS的构造。演示了XVCS和EXVCS的基本矩阵，以及像素扩展和对比度。说明了相关方法之间的比较，以显示所提出方案的优点。