An Effective chaos-based image watermarking scheme using fractal coding

AbstractThe image watermarking technology is a technique of embedding hidden data in an original image. In this paper, a new watermarking method for embedding watermark bits based on Chaos-Fractal Coding is given. A chaotic signal is defined as being deterministic, pseudo periodic and presenting sensitivity to initial conditions. Combining a chaos system with Fractal Coding plays an important role in the security, invisibility and capacity of the proposed scheme. The main idea of the new proposed algorithm for coding is to determine a set of selective blocks for steady embedding. Simulation results show that the CFC algorithm (Chaos-Fractal Coding) has a confident capacity. The embedding technique that proposed in this paper is quite general, and can be applied to the extracting scheme with demanded changes

A Color Image Watermarking Scheme Based On QR Factorization, Logistic and Lorentz Chaotic Maps

Most of the existing color image watermarking schemes use grayscale or binary image as watermark because color image watermark has more data than grayscale or binary watermark. Therefore, it is a challenging issue to design a color image-watermarking scheme. This paper proposes a novel color image watermarking scheme to embed color image watermark into color host image. In watermarking schemes, first divide the host and watermark image into non-overlapping blocks, apply the Discrete Cosine Transformation (DCT) on each blocks of both watermark, and host image. After that QR Factorization, apply on the each blocks of watermark. In this paper, Logistic and Lorentz chaotic maps are usedfor estimating the embedding strength and location. The experimental results reveal that this watermarking scheme is robust against different image processing attacks viz. cropping, contrast adjustment and coloring