A new medical image watermarking scheme for a better telediagnosis

摘要

In the ethical code of medicine, the Hippocras vow integrates the confidentiality principle of medical information. For this, it was generally admitted that the security granted to the electronic patients files must be higher than that applied to usual paper files. Actually, secure transmission Systems are insufficient toward requirements and softness of this sector (security, integrity, safety,...). In this work, we propose a new technique allowing to transfer medical images in a safe way. This method is based on watermarking. It guarantees the information integrity and escape the possible false affiliations between the patient image and the medical folder. The patient data represent the information we will try to embed in the image. For this, we need to scramble it with a Pseudo Aleatory Binary Sequence with a private key. After that we apply on these data an encryption technique (here, we have used RSA method). Since, we must embed the mark in the host image. In order to assure the imperceptibility of the mark, we have choose to add a virtual border to the image and to inser the encrypted data in the LSB of each pixel. With this method, we are sure that, in one part, we have an imperceptible watermark, and in the other hand, we haven't after the image quality. For the embedding scheme, we need to encode the patient data (before scrambling and encrypting them). Since, we have elaborated an encoder scheme on 6 bits. In this work, one presented a new method using of the watermarking techniques in order to ensure the protected transfer of the medical images with data relating to the patient for telediagnosis. It was shown that the technique suggested does not influence the quality of the final image after deciphering nor the data that it contains. The method was illustrated and tested on 42 Dicom images that we have watermark by inserting the patient data. The watermarked images show that no perceptual difference where observed even after being tested by several attacks. When extracting the mark, the patient data were preserved and 0 bit errors were detected.