Digital Image Security Using Digital Watermarking
ABSTRACT: Digital image watermarking process is definite as to insert information of digital into digital signal. In watermarking is defined as a technique which embeds data into digital contents such as text, still images, video and audio data without degrading the overall quality of the digital media. This is an efficient solution to avoid illegal copying of information from multimedia networks. Digital image safety and integrity the top prioritized issue in today’s information explosion. Watermarking is a popular technique that is used for copyright protection and authentication. Watermark should be robust and imperceptible. Robustness of watermark can be explained in terms of successful recovery of watermark from recovered content which may contain different types of noises and compression effects. This paper presents an overview of the various concepts and research works in the field of image watermark authentication. Index Terms— Watermarking, Spatial domain, Image Transforms, Discrete Wavelet Transform, Discrete Cosine Transform, Discrete Fourier Transform 1. INTRODUCTION: A digital watermark is a kind of marker covertly embedded in a noise-tolerant signal such as an audio, video or image data. It is typically used to identify ownership of the copyright of such signal. "Watermarking" is the process of hiding digital information in a carrier signal the hidden information should, but does not need to, contain a relation to the carrier signal. Digital watermarks may be used to verify the authenticity or integrity of the carrier signal or to show the identity of its owners. The information to be embedded in a signal is called a digital watermark, although in some contexts the phrase digital watermark means the difference between the watermarked signal and the cover signal. The signal where the watermark is to be embedded is called the host signal. A watermarking system is usually divided into three distinct steps, embedding, attack, and detection. In embedding, an algorithm accepts the host and the data to be embedded, and produces a watermarked signal.