摘要：

相对于自然载体无载体信息隐藏, 非自然载体无载体信息隐藏不试图生成或利用自然载体来隐藏秘密信息, 可从根本上杜绝自然载体判别问题。但在现有的非自然载体无载体信息隐藏方法中, 水影画嵌密无法对秘密信息进行有效掩盖, 分形嵌密需满足整体与局部自相似的严苛数学约束。为对秘密信息进行有效掩盖并进一步提升视觉质量, 采用自然图像矢量化的方式, 提出一种结合三角剖分和贝塞尔曲线嵌密的石头画生成式信息隐藏方法。首先, 将前景区域三角剖分, 剔除不适合嵌密和不保持掩体前景特征的三角区域; 其次, 产生表征秘密比特且与给定三角区域相内切的石头轮廓, 并填充与三角区域、密钥、嵌密比特一致的随机颜色, 从而产生石头画; 最后, 基于密钥产生一致的三角区域, 提取秘密比特并进行颜色认证。理论和实验结果表明, 该方法可产生与掩体图像轮廓特征一致的富含语义的石头画, 且不暴露嵌密特征, 同时可对秘密信息进行有效掩盖, 特征提取严格依赖于密钥, 可对提取的秘密比特进行高精度的颜色认证, 未知密钥将无法获取秘密信息。

关键词: 无载体信息隐藏, 三角剖分, 贝塞尔曲线, 颜色认证, 石头画

Abstract:

Unlike natural carrier-based coverless information hiding, non-natural carrier-based coverless information hiding does not attempt to generate or utilize natural carriers to hide secret information, which can fundamentally avoid the discrimination problem of natural carriers. However, in existing non-natural-based coverless information hiding methods, marbling painting based information hiding cannot conceal secret bits effectively, whereas fractal-based information hiding requires strict mathematical constraints on global and local self-similarities. To effectively conceal secret information and further improve visual quality by employing natural image vectorization, this paper proposes a stone painting generative information hiding method through triangulation and Bezier curves. First, the foreground region of a cover image is triangulated by removing triangles that are unsuitable for embedding and do not preserve foreground characteristics. Second, stone contours that represent the secret bits and are tangential to the given triangular region are generated, and random colors consistent with the triangular region, user key, and embedded secret bits are filled in to generate the stone painting. Finally, the secret bits are extracted, and color authentication is performed based on the consistent triangular region generated by the key. Theoretical and experimental results confirm that the proposed method can generate stone paintings with semantically rich features consistent with the contours of the cover image. It effectively conceals secret bits without exposing the embedded features, and the extraction relies strictly on the user key, thereby allowing high-precision color authentication. Without the correct key, the secret bits cannot be obtained.

Key words: coverless information hiding, triangulation, Bezier curve, color authentication, stone painting