The protection of 3D contents from illegal distribution has attracted considerable attention and depth-image-based rendering (DIBR) is proved to be a promising technology for 3D image and video displaying. In this paper, we propose a new digital watermarking scheme for DIBR 3D images based on feature regions and ridgelet transform (RT). In this scheme, the center view and the depth map are made available at the content provider side. After selecting the reference points of the center view, we construct the feature regions for watermark embedding. Considering the sparse image representation and directional sensitivity of the RT, the watermark bits are embedded into the amplitudes of the ridgelet coefficients of the most energetic direction. The virtual left and virtual right views are generated from the watermarked center view and the associated depth map at the content consumer side. The watermarked view has good perceptual quality under both the objective and subjective image quality evaluations. The embedded watermark can be detected blindly with low bit error rate (BER) from the watermarked center view, the synthesized left and right views even when the views are distorted and distributed separately. The experimental results demonstrate that the proposed scheme exhibits good performance in terms of robustness against various image processing attacks. Meanwhile, our method can be robust to common DIBR processing, such as depth image variation, baseline distance adjustment and different rendering conditions. Furthermore, compared with other related and state-of-the-art methods, the proposed algorithm shows higher accuracy in watermark extraction.

保护3D内容免遭非法分发已经引起了广泛关注，基于深度图像的渲染（DIBR）被证明是3D图像和视频显示的有前途的技术。在本文中，我们提出了一种基于特征区域和脊波变换（RT）的DIBR 3D图像数字水印新方案。在该方案中，中心视图和深度图在内容提供者侧可用。选择中心视图的参考点后，我们构造了用于水印嵌入的特征区域。考虑到RT的稀疏图像表示和方向敏感性，水印位被嵌入到最充满活力的方向的脊波系数的幅度中。虚拟左视图和虚拟右视图是从加水印的中心视图和内容消费者方的关联深度图生成的。在客观和主观图像质量评估下，带水印的视图均具有良好的感知质量。可以从加水印的中心视图，合成的左视图和右视图以低误码率（BER）盲目检测嵌入的水印，即使这些视图分别失真和分布。实验结果表明，该方案在针对各种图像处理攻击的鲁棒性方面表现出良好的性能。同时，我们的方法对于常见的DIBR处理（如深度图像变化，基线距离调整和不同的渲染条件）可能是可靠的。此外，与其他相关的最新技术相比，