This paper proposes a high-capacity reversible data hiding scheme for encrypted images using pixel predictions and Huffman encoding. At the owner's side, we propose to generate the prediction-error histogram (PEH) of the original image using the median edge detector (MED). According to the prediction errors, we divide the pixels into independently encoding pixels and jointly encoding pixels. We then build an optimal Huffman tree to efficiently encode the prediction errors. Then the image is encrypted using the stream cipher and an image encryption key. We replace the lower bit-planes of the encrypted pixels with the Huffman codeword of their prediction error. The rest of the bit-planes are vacated as the embedding room. At the data hider's side, we locate the vacated room with the reference of the side information. We then encrypt the additional data using the data hiding key and embed it into the encrypted image. The proposed scheme is separable, namely, the receivers with different authentication can respectively conduct error-free data extraction and/or error-free image recovery. The results show that the embedding capacity of the proposed scheme is larger than previous RDHEI arts. Besides, the proposed scheme can provide high information security. Little detail of the original image can be discovered from the encrypted image by the unauthorized users.

中文翻译：

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使用像素预测和霍夫曼编码将高容量可逆数据隐藏在加密图像中

本文提出了一种使用像素预测和霍夫曼编码的加密图像大容量可逆数据隐藏方案。在所有者方面，我们建议使用中值边缘检测器（MED）生成原始图像的预测误差直方图（PEH）。根据预测误差，我们将像素分为独立编码像素和联合编码像素。然后，我们建立一个最佳霍夫曼树，以有效地编码预测误差。然后，使用流密码和图像加密密钥对图像进行加密。我们用其预测误差的霍夫曼码字替换加密像素的低位平面。其余位平面被腾出作为嵌入室。在数据隐藏器的一侧，我们通过参考辅助信息来定位空出的房间。然后，我们使用数据隐藏密钥对其他数据进行加密，并将其嵌入到加密的图像中。所提出的方案是可分离的，即具有不同认证的接收器可以分别进行无错误的数据提取和/或无错误的图像恢复。结果表明，该方案的嵌入能力大于现有的RDHEI技术。此外，该方案可以提供较高的信息安全性。未经授权的用户可以从加密图像中发现原始图像的很少细节。结果表明，该方案的嵌入能力大于现有的RDHEI技术。此外，该方案可以提供较高的信息安全性。未经授权的用户可以从加密图像中发现原始图像的很少细节。结果表明，该方案的嵌入能力大于现有的RDHEI技术。此外，该方案可以提供较高的信息安全性。未经授权的用户可以从加密图像中发现原始图像的很少细节。