Accessibility and ease of internet, together with availability of relatively inexpensive digital recording and storage devices has created an environment where duplication, unauthenticated use and maldistribution of digital content has become very easy. This also facilitates unauthorized use, misappropriation, misrepresentation. Thus authentication of multimedia contents (such as image, video, ...

In the last decade, we have seen a tremendous growth in color and color-based applications within the signal, image and video processing communities. Color is no longer interpreted as an extension of gray scale and is now considered as a key element for a number of image and video processing systems. In particular, color space transforms have played a central role in coding, compression and tra...

Accessing various multimedia contents is something very essential in our daily life. However, delivery of multimedia contents consumes lots of network bandwidths. Therefore, compression of multimedia is very essential, and also an inevitable task for real applications. Moreover, due to the noise induced during the transmission of data, reliable transmission of compressed multimedia is also an i...

In this paper, an imperceptible, fragile text watermarking algorithm has been proposed. The font color of each alphabet in the text document is varied in the greyscale in accordance with a sine function. The amplitude for the same is generated using a hash function. The authenticity of the received document can be verified by comparing the actual color values of the letters in the document with...

The intriguing characteristics of chaotic maps have prompted researchers to use these sequences in watermarking systems to good effect. In this paper we aim to use a tent map to encrypt the binary logo to achieve a like-noise signal. This approach makes extraction of the watermark signal by potential attacker very hard. Embedding locations are selected based on certain principles. Experimental ...

Information theoretic methods of calculating the capacity of data hiding schemes allow for objective comparisons of watermarking algorithms. This paper applies these methods to the case of colour image watermarking, using a dual tree complex wavelet transform and non redundant complex wavelet transform along with a spread transform data hiding algorithm to compare levels of capacity between the...

In digital watermarking, a major aim is to insert the maximum possible watermark signal while minimizing visibility. Many watermarking systems embed data in the luminance channel to ensure watermark survival through operations such as grayscale conversion. For these systems, one method of reducing visibility is for the luminance changes due to the watermark signal to be inserted into the colors...

This paper presents a high dynamic range (HDR) image zero watermarking method based on dual tree complex wavelet transform (DT-CWT) and quaternion. In order to be against tone mapping (TM), DT-CWT is used the three RGB color channels of HDR for obtaining low-pass sub-bands, respectively, since can extract contour change small after TM. The provides wide range, thus, three-color channel correlat...