Digital Watermark is an invisible mark inserted into the digital multimedia data so that it can be detected in the later stage of evidence of rightful ownership. A great deal of research efforts has been focused on digital watermark in recent years. The techniques proposed so far can be divided into two main groups 
of according to the embedding domain of the container image.
1) Spatial Domain Approach:-
One group is SPATIAL domain approach .The earliest watermarking techniques are mainly this kind and the simplest example is to embed the watermark into least significant bits(LSB) of the image pixels. However, this technique has relatively low information hiding capacity and can be easily erased by lossy image compression.
2) Frequency Domain Approach:
The other group is FREQUENCY domain approach. This can embed more information bits and is relatively robust to attacks. They embedded a Guassian distributed sequence into the perceptually most significant frequency components of the container image. Another technique embedded an image watermark into selectively modified middle frequency of discrete cosine transform coefficients. One more algorithm embedded watermark using Fourier transformations that is invariant to image manipulations or attacks due to rotation scaling and translation. Still several methods used to hide the data to the frequency domain such as HVS, JND.
PROPOSED SYSTEM: -
Due to above mentioned failures a new technique has been proposed so that to cover and maintain the drawbacks prevailed in the previous system and hence a technique called Fast Hadamard Transformation proposed. This algorithm is often referred as robust one because of its following properties and attributes that meets the requirements.
Fast Hadamard Transform (FHT) is a watermarking approach proposed in a conference paper developed by Datamark Technologies Pvt Ltd, Singapore. In this paper we propose a fast Hadamard transform based watermarking approach that embeds a gray scale image as a watermark. The watermark gray scale image is decomposed into Hadamard coefficients for embedding.
To increase the invisibility of he water mark a visual model based on the original image charecterstics, such as edges and textures are incorporated to determine the watermarking strength factor. This factor is used to scale the watermark coefficients in a similar range to the coefficients from Hadamard coefficients of the sub blocks of the container image.
The FHT embedding algorithm was found to provide a robust and efficient approach to perform digital watermarking of digital image data for copyright protection and proof of rightful ownership. The simplicity of FHT offers a significant advantage in shorter processing time and ease of hardware implementation than most orthogonal transform techniques such as DCT and DWT.
The Hadamard transform has more useful middle and high frequency bands than several high gain transforms, such as DCT.When compared with the DCT, it found to be more robust against various attacks .It also offers a significant advantage in term of a shorter processing time and the ease of hardware implementation than many common transformation techniques.
of according to the embedding domain of the container image.1) Spatial Domain Approach:-
One group is SPATIAL domain approach .The earliest watermarking techniques are mainly this kind and the simplest example is to embed the watermark into least significant bits(LSB) of the image pixels. However, this technique has relatively low information hiding capacity and can be easily erased by lossy image compression.
2) Frequency Domain Approach:
The other group is FREQUENCY domain approach. This can embed more information bits and is relatively robust to attacks. They embedded a Guassian distributed sequence into the perceptually most significant frequency components of the container image. Another technique embedded an image watermark into selectively modified middle frequency of discrete cosine transform coefficients. One more algorithm embedded watermark using Fourier transformations that is invariant to image manipulations or attacks due to rotation scaling and translation. Still several methods used to hide the data to the frequency domain such as HVS, JND.
PROPOSED SYSTEM: -
Due to above mentioned failures a new technique has been proposed so that to cover and maintain the drawbacks prevailed in the previous system and hence a technique called Fast Hadamard Transformation proposed. This algorithm is often referred as robust one because of its following properties and attributes that meets the requirements.
Fast Hadamard Transform (FHT) is a watermarking approach proposed in a conference paper developed by Datamark Technologies Pvt Ltd, Singapore. In this paper we propose a fast Hadamard transform based watermarking approach that embeds a gray scale image as a watermark. The watermark gray scale image is decomposed into Hadamard coefficients for embedding.
To increase the invisibility of he water mark a visual model based on the original image charecterstics, such as edges and textures are incorporated to determine the watermarking strength factor. This factor is used to scale the watermark coefficients in a similar range to the coefficients from Hadamard coefficients of the sub blocks of the container image.
The FHT embedding algorithm was found to provide a robust and efficient approach to perform digital watermarking of digital image data for copyright protection and proof of rightful ownership. The simplicity of FHT offers a significant advantage in shorter processing time and ease of hardware implementation than most orthogonal transform techniques such as DCT and DWT.
The Hadamard transform has more useful middle and high frequency bands than several high gain transforms, such as DCT.When compared with the DCT, it found to be more robust against various attacks .It also offers a significant advantage in term of a shorter processing time and the ease of hardware implementation than many common transformation techniques.
