1. A reversible data hiding method by histogram shifting in high quality medical images Author: Li-Chin Huang, Lin-Yu Tseng, Min-Shiang Hwang Source: The Journal of Systems and Software, 2013 Reporter: Min-Hao Wu

2. Outline Introduction Proposed scheme Experimental results Conclusion

3. Introduction Most hospitals have already established the electronic medical information to make healthcare better, safer, and more efficient. Over the Internet, digitized medical information is very convenient to transmit among patients, medical professionals, health care providers, and institutes of medicine. Data hiding plays an important role in information security such as authentication, fingerprinting, copy control, security, and covert communication.

4. Introduction (cont.) Reversible data hiding, which is also called lossless data hiding Reversible data hiding techniques can be classed into three groups data compression (VQ) pixel-value difference expansion (DE) histogram-based scheme

5. Introduction (cont.) DE is one kind of integer wavelet transform proposed by Tian high-capacity and low-distortion reversible watermarking redundancy in digital images by expanding the difference between the two neigh- boring pixel pairs to achieve a high-capacity and low-distortion reversible watermarking

6. Introduction (cont.) Histogram shifting is another technique applied in reversible watermarking schemes In 2006 Ni proposed a zero and a peak point of image histogram to embed messages. In 2011 Luo proposed exploits the high correlation among image block pixels to produce a difference histogram and embedded secret data by a multi- level histogram shifting mechanism.

7. Proposed scheme Reversible data hiding in medical image (1) well-suited for high quality medical images, (2) without salt-and-pepper, (3) applicable to medical image with smooth surface, (4) well-suited sparse histogram of intensity levels, (5) free location map, (6) ability of adjusting data embedding capacity, PSNR and Inter-Slice PSNR.

8. Proposed scheme (cont.)

11. http://140.134.50.88/report/counter.php?arg=1782:report/data/report/2013-3- 21/A%20reversible%20data%20hiding%20method%20by%20histogram%20shifting%20in%20high%20qual ity%20medical%20images(for%20print).pdf

12. Proposed scheme (cont.)

19. The strategy of data embedding where k is threshold and ˛ is difference value.

21. Proposed scheme (cont.)

23. Experiment results

24. Experiment results (cont.)

26. Conclusion Sign and unsign 16-bit depth high quality medical images with dicom format are tested on our algorithm. well-suited for high quality medical images and without salt-and-pepper. the utilization rate and histogram shift to solve underflow/overflow problem.