A new wavelet based logo-watermarking scheme for copyright protection of digital image is presented. Instead of using a noise type Gaussian sequence, a visually meaningful gray scale logo is used as watermark. Watermark embedding process is carried out by transforming both the image and logo in wavelet domain. To embed the watermark robustly and imperceptibly, watermark bits are added to the significant coefficients of each subband selected by considering the human visual system (HVS) characteristics. A scheme is developed for reliable extraction of watermark from distorted images. From the experimental results it can be observed that proposed method is robust to wide variety of attacks. Comparison with the existing methods shows the superiority of the proposed method. Ó 2004 Elsevier B.V. All rights reserved.

This paper presents a novel invisible robust watermarking scheme for embedding and extracting a digital watermark in an image. The novelty lies in determining a perceptually important subimage in the host image. Invisible insertion of the watermark is performed in the most significant region of the host image such that tampering of that portion with an intention to remove or destroy will degrade the esthetic quality and value of the image. One feature of the algorithm is that this sub-image is used as a region of interest for the watermarking process and eliminates the chance of watermark removal. Another feature of the algorithm is the creation of a compound watermark using the input user watermark (logo) and attributes of the host image. This facilitates the homogeneous fusion of a watermark with the cover image, preserves the quality of the host image, and allows robust insertion-extraction. Watermark creation consists of two distinct phases. During the first phase, a statistical image is synthesized from a perceptually important sub-image of the image. A compound watermark is created by embedding a watermark (logo) into the statistical synthetic image by using a visible watermarking technique. This compound watermark is invisibly embedded into the important block of the host image. The authentication process involves extraction of the perceptive logo as well statistical testing for two-layer evidence. Results of the experimentation using standard benchmarks demonstrates the robustness and efficacy of the proposed watermarking approach. Ownership proof could be established under various hostile attacks.

This paper presents a composite blind digital watermarking technique, CompMark, to hide a visually meaningful grayscale logo in a host image. The multi-resolution fusion principles are used to embed the grayscale logo in perceptually significant blocks in wavelet subbands of the host image. A modulus approach is further used to embed a binary counterpart of the logo in the approximation subband. The extraction process combines both extracted grayscale and binary logos to obtain a better, recognizable logo at the receiver. The watermark detection decision is based on either the correlation between the thresholded extracted and embedded logos or the visual similarity. Experimental results demonstrate our scheme is robust against compression, white noise addition, histogram equalization, and image filtering techniques. In addition, it performs better than a peer blind scheme, XFuseMark. Index Terms — Grayscale logo watermarking, modulus embedding, additive fusion principles

Abstract: Problem statement: The issue of having robust and fragile watermarking is still main focus for various researchers worldwide. Performance of a watermarking technique depends on how complex as well as how feasible to implement. These issues are tested using various kinds of attacks including geometry and transformation. Watermarking techniques in color images are more challenging than gray images in terms of complexity and information handling. In this study, we focused on implementation of watermarking technique in color images using the biological model. Approach: We proposed a novel method for watermarking using spatial and the Discrete Cosine Transform (DCT) domains. The proposed method deled with colored images in the biological color model, the Hue, Saturation and Intensity (HSI). Technique was implemented and used against various colored images including the standard ones such as pepper image. The experiments were done using various attacks such as cropping, transformation and geometry. Results: The method robustness showed high accuracy in retrieval data and technique is fragile against geometric attacks. Conclusion: Watermark security was increased by using the Hadamard transform matrix. The watermarks used were meaningful and of varying sizes and details.

This paper is based on a comparative study between different watermarking techniques such as LSB hiding algorithm, (2, 2) visual cryptography based watermarking for color images [3,4] and Randomized LSB-MSB hiding algorithm [1]. Here, we embed the secret image in a host or original image, by using these bit-wise pixel manipulation algorithms. This is followed by a comparative study of the resultant images through Peak Signal to Noise Ratio (PSNR) calculation. The property wise variation of different types of secret images that are embedded into the host image plays an important role in this context. The calculation of the Peak Signal to Noise Ratio is done for different color levels (red, green, blue) and also for their equivalent gray level images. From the results, we are trying to predict which technique is more suitable to which type of secret image.

networks enhance the development of the information technology in different areas. Sometimes the digital data can be easily used to copied, modified and distributed in an illegal way. The copy right protection, intellectual protection and material right protection for authors, owners, buyers and distributors is necessary and the authenticity of content or matter are crucial factors to solving problem. In such case the digital watermarking techniques play an important role as a valid solution. In this paper, we introduce a suitable method of watermarking because the watermark protects the copyright of digital products and the integrity of certification. The main focused of Watermarking is developing and introducing new techniques for watermark embedding and detection. Experimental results show that the embedded watermark is transparent and quite robust in face of various watermark images at high compression ratios and provides good results in terms of imperceptibility.