Robust and imperceptible color image watermarking for telemedicine applications

Abstract

Watermarking is effective method to hide the confidential information into some multimedia at sending side and later extracted at the receiver side to fulfill various requirements. Several algorithms have been proposed by many scholars for embedding watermark in spatial as well as frequency domain. Frequency domain embedding algorithms are more robust against attacks hence, researcher proposed to hide the information in frequency domain. The protection of patient details is most crucial to encourage the telemedicine application. For telemedicine application we need to hide patient's detail in the medical cover image without damaging the imperceptibility of medical image. In this paper we present a watermarking technique by considering the proportion of color contribution to the luminance of image to address imperceptibility and for robustness we have applied Discrete Wavelet Transform (DWT) up to the second level of decomposition. In this paper we hide the patient's personal information as watermark in grey scale in the specific ratio in the RGB components of the cover medical color image to increase the hiding capacity. We obtain improved robustness and higher hiding capacity in the proposed approach while at the same time imperceptibility of the color medical image is maintained. To analyze the proposed watermarking technique Normalized-Cross-Correlation (NC) and Peak-signal-to-noise-ratio (PSNR) are used as the performance parameters.