An improved DWT-SVD domain watermarking for medical information security

Exchange of patient record over network required a technique to guarantee security and privacy for tele-health services. This paper presents an improved watermarking technique capable of providing protection of patient data by embedding multi -watermarks in medical cover image using DWT-SVD domain. Prior to embedding, Hamming code is applied to text watermark in order to reduce channel noise distortion for the sensitive data. After embedding, the watermarked medical image is encrypted then compressed. Out of two encryption method and three compression scheme tested, combination of Chaotic-LZW shows the best performance. However, HyperChaotic-LZW combination is more robust against Gaussian, JPEG compression, speckle noise and histogram equalization attacks. We illustrate the good results in terms of objective and subjective evaluation, and verify its robustness for various attacks while maintaining imperceptibility, security and compression ratio. Experimental results demonstrate that the suggested technique archives high robustness against attacks in comparison to the other scheme for medical images.