A novel lossless robust watermarking method for copyright protection of biomedical image

Nanoscience and Nanotechnology promotes the development of biomedical imaging devices, more and more valuable biomedical images are transmitted through the open network, and their copyright suffers a major challenge. This paper proposes a new lossless robust watermarking method to realize biomedical image's copyright protection. For high-resolution biomedical images, the redundant theory and histogram shifting method based on image block's difference are utilized to repeatedly embed copyright watermark into different color channels. In the extracting procedure, each layer's watermark information can be extracted from watermarked image respectively, and the final watermark is judged by the voting theory. The redundant scheme and voting theory guarantees the watermark can resist against random noise's attack well. Besides, in order to reduce the watermark overhead in embedding procedure, the histogram narrowing down technique is used to tackle with those image blocks would overflows and underflows. Experimental results showed that the proposed method outperformed the existing semi-fragile reversible watermarking scheme and provided a great robustness against moderate JPEG compression and salt-pepper and Gaussian noise.