%0 Journal Article %A CHEN Na %A LI Qi %A YAN Bin %A YANG Hongmei %T 3D medical image reversible watermarking algorithm based on unidirectional prediction error expansion %D 2019 %R 10.11772/j.issn.1001-9081.2018071471 %J Journal of Computer Applications %P 483-487 %V 39 %N 2 %X For the application of reversible watermarking technology in three-Dimensional (3D) medical images, a 3D medical image reversible watermarking algorithm based on unidirectional prediction error expansion was proposed. Firstly, the intermediate pixels were predicted according to the 3D gradient changes between them and their neighborhood pixels to obtain the prediction errors. Then, considering the features of the 3D medical image generated by magnetic resonance imaging, the external information was embedded into the 3D medical image by combining unidirectional histogram shifting with prediction error expansion. Finally, the pixels were re-predicted to extract the external information and restore the original 3D image. Experimental results on MR-head and MR-chest data show that compared with two-dimensional (2D) gradient-based prediction, the mean absolute deviation of prediction error produced by 3D gradient-based prediction are reduced by 1.09 and 1.40, respectively; and the maximal embedding capacity of each pixel is increased by 0.0456 and 0.1291 bits, respectively. The proposed algorithm can predict the pixels more accurately and embed more external information, so it is applicable to 3D medical image tempering detection and privacy protection for patients. %U http://www.joca.cn/EN/10.11772/j.issn.1001-9081.2018071471