Watermarking and steganography in images

In this thesis, digital watermarking and steganography techniques had been explained and an application had been applied. Due to the rapid development of the digital technologies, digital products become very popular and it is easy to create, transmit, duplicate, and manipulate digital videos, photos, voices, and so on. Such convenience however leads to a problem, that is, it is also easy to tamper with the content of a digital product. The situation can be very serious especially when the media content is critical. Many researchers are aware of the issues of copyright protection, image authentication, proof of ownership, etc. Hence, there are many solutions that have been proposed. The watermarking technique is one of the solutions. This technique embeds information so that it is not easily perceptible; that is, the viewer cannot see any information embedded in the contents. Digital watermarking refers to specific information hiding techniques whose purpose is to embed secret information inside multimedia content, like images, video, or audio data. Steganography is the art and science of hiding information such that its presence cannot be detected and a communication is happening. The main goal of steganography is to communicate securely in a completely undetectable manner and to avoid drawing suspicion to the transmission of a hidden data. It is not to keep others from knowing the hidden information, but it is to keep others from thinking that the information even exists. Steganography and digital watermarking are very similar; however one big distinction must be highlighted between the two. In digital watermarking, the focus is on ensuring that nobody can remove or alter the content of the watermarked data, even though it might be plainly obvious that it exists. Steganography on the other hand, focuses on making it extremely di?cult to tell that a secret message exists at all. If an unauthorized third party is able to say with high con?dence that a ?le contains a secret message, then steganography has failed. Proposed method in this thesis we applied to an image both methods. Digital watermarking detects whether or not the data in image. And steganography is used to transmit the secret message.