Abstract
Digital image watermarking is one of the prime areas of research in the field information security and data authentication. There exist different methods to embed watermark information in the image. Image imperceptibility is a factor that limits the amount of information being embedded in the image. There is as such no closed form formula or expression in the literature that could relate image imperceptibility and capacity of watermark information. In this paper, a novel technique is proposed in which a second order fuzzy rule based system (SOFRBS) is designed to maximize the capacity of image based characteristics of upon human visual system (HVS) and desired peak signal to noise ratio (PSNR) which is coined as imperceptibility factor (IF). First order fuzzy rule based system (FOFRBS) calculates the capacity factor, alpha by taking the brightness, edge and texture sensitivity as input, while second order fuzzy rule based system (SOFRBS) calculates the capacity by taking alpha and IF as input. Moreover, the proposed scheme is also robust against JPEG compression attack. The authenticity of the proposed scheme is validated through simulation of different types of images like natural and medical images.