Imperceptible digital watermarking in medical retinal images for tele-medicine applications

This paper proposes a method of inserting a digital pattern having patient identity information in the medical retinal image without changing the perceptual property and without causing any loss of medical information of this image. To achieve this insertion of the digital signature identity of the patient is done in the singular value based decomposition (SVD) domain of the image. After the insertion of this digital signature is done in the retinal image a detailed comparative study and analysis is done between original image and marked image to test if all the medical information and features of the image is retained. The important feature of the medical image like blood arteries, macula and optic disc has been segmented from the original and stego-image. The experimental results indicate that the original and the stego image have similar perceptual properties and no medical information is lost in the process of digital watermarking. Features of the original and stego image has been analyzed and experimental results indicates that the variation in the features is minimal and do not affect the medical information which has been validated by professional ophthalmologists. The correlation of the features extracted is above 0.99 indicating the insertion of the digital pattern did not cause any loss of medical information in the image.