This paper proposes a novel reversible data hiding (RDH) scheme in encrypted domain for medical DICOM images. Although a lot of RDH schemes for encrypted images have been presented, however, most of them are unsuitable for medical DICOM images, as they do not utilize the features of the DICOM image format, and the recovery accuracy is low because medical images have large areas with the same pixel values. To avoid these weaknesses, our scheme segments the image and only embeds data into part of the encrypted image. The redundancy of pixel cells in DICOM images is exploited so that auxiliary data can be embedded into the image. The order of data extraction and image recovery, which can be optimized by the number of recovered blocks around the unrecovered block, is calculated to improve the recovery accuracy. In addition, to ensure the integrity of the DICOM image, the hash value of the minimum bounding rectangle of ROI and the feature bit matrix of the rest are calculated. If the image is tampered, the tampered area, especially ROI, can be accurately detected and located on the receiver side. Experimental results demonstrate the effectiveness of the proposed scheme.

中文翻译：

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隐藏在加密医学 DICOM 图像中的可逆数据

本文提出了一种新的医学 DICOM 图像加密域可逆数据隐藏 (RDH) 方案。虽然已经提出了很多用于加密图像的 RDH 方案，但是它们中的大多数不适合医学 DICOM 图像，因为它们没有利用 DICOM 图像格式的特征，并且由于医学图像面积大，恢复精度低具有相同的像素值。为了避免这些弱点，我们的方案对图像进行了分割，并且只将数据嵌入到加密图像的一部分中。利用 DICOM 图像中像素单元的冗余，以便可以将辅助数据嵌入到图像中。计算数据提取和图像恢复的顺序，可以通过未恢复块周围的恢复块数进行优化，以提高恢复精度。此外，为保证DICOM图像的完整性，计算ROI的最小包围矩形的哈希值和其余的特征位矩阵。如果图像被篡改，被篡改的区域，尤其是 ROI，可以在接收端被准确地检测和定位。实验结果证明了所提出方案的有效性。