Santi P. Maity received his B. E. degree in Electronics and Communication Engineering from National Institute of Technology, Durgapur (formerly known as REC Durgapur) and M. Tech in Microwaves with specialization in digital communication, from the University of Burdwan, West Bengal, India in 1993 and 1997, respectively. He did his Master project in Time and Frequency Section, National Physical Laboratory, New Delhi, India in 1997. He received his Ph. D degree in Engineering from Indian Institute of Engineering Science and Technology, Shibpur (formerly Bengal Engineering and Science University, Shibpur), India in 2008 in association with Machine Intelligence Unit, Indian Statistical Institute, Kolkata. He received couple of Post-Doctoral research positions in different universities-Nanyang Technological University, Singapore; Laboratoire des Signaux et Systems, France and University of Vigo, Spain. He did his Post-Doctoral research for one year (January 2009 to July 2009 and February 2011 to July 2011) in the “Laboratoire des Signaux et Systems (CNRS-Supelec-Universite Paris-Sud 11)” in France. He is at present working as Professor since September, 2012 in Indian Institute of Engineering Science and Technology, Shibpur, India. He was Head for the Department of Information Technology in IIEST, Shibpur from February, 2012 to 1st February, 2014. His research interests include multicarrier (MC)-CDMA, Cognitive Radio Networks, Compressive Sampling, Digital Watermarking, Secret Sharing, Medical Image Reconstruction at Compressed Sensing and Segmentation, Blood Vessels and Lesion Detection on Retinal Images. He has published about 190 research papers in International Journals and Conferences including IEEE Transactions/Journals, Letters, Elsevier Science, Springer Verlag, World Scientific etc. He completed successfully the Govt. of India sponsored project on Wireless Communication (MC-CDMA) as Principal Investigator on 2008-2010, supervised several Master and 6 Ph. D thesis and many others are working for Ph. D. He has delivered about 40 invited lectures and tutorial talk in International and National Conferences, National Seminars, Workshops, Faculty Development Programs and acted as Coordinator, TPC Member, Program Chair(s) and General Chair(s) in International Conferences.
Depending on its robustness, a watermark can be classified as fragile, semi-fragile or robust. A Fragile watermark cannot resist any attacks on the mark and may be manipulated before reaching the receiver. A semi-fragile watermark is able to endure certain types of attacking techniques and cannot resist some others. A Robust watermark is able to resist virtually all possible kinds of attack techniques.
According to the key usage, the watermarking could be symmetric or asymmetric. In symmetric watermarking the same keys are used for embedding and detecting the watermark. In asymmetric watermarking, different keys are used for embedding and detecting the watermark.
Watermarking procedures are based on using key information. They require a user key during both the insertion and the extraction procedures. If the correct key is specified in the watermark extraction procedure it returns the right watermark. If the key is incorrect the extracted watermark looks like random noise. The conventional digital watermark systems use a technique like common-key cryptography. There are both secret and public key authentication watermarking schemes.
Watermarking robustness is a measure of a watermarks ability to be virtually immune to a variety of processing operations or attacks. The watermark must remain through general signal processing operations (JPEG compression, cropping, etc.), geometric transformation and malicious attack.
We provide a survey of the current state of the art in natural language watermarking and introduce terminology, techniques, and tools for text processing.
Algorithms for watermarking may be based on a spatial domain or a transformed domain. Spatial domain watermarking modifies the pixel values of one or many randomly selected subsets of images. It directly loads the raw data into the image pixels. It could be based on using different patches or least significant bit planes. Transform domain watermarking is based on transform coefficient alteration. There are several commonly used transform domain methods, such as DCT or DWT.
This approach is different from techniques, collectively referred to as "text watermarking," which embed information by modifying the appearance of text elements, such as lines, words, or characters.
Watermarks can also be classified as one of two types, noise or image/video. A Noise type is based on pseudo noise information such as Gaussian or chaotic sequences. An Image/Video type has watermark information represented as an image or motion image, usually a binary image that represents a stamp, logo or label.
There are different types of watermarking including visible, invisible and dual. A visible watermark is clearly visible on a watermarked image/video, whereas an invisible watermark is hidden and virtually indistinguishable from the image/video. Dual watermarking is a combination of visible and invisible.
Digital watermarking, on the other hand, is embedded so that the information becomes virtually indistinguishable for users of the source information. Although detectable, it is not possible to remove the hidden information even by applying strong transformation of the watermarked information.
Digital watermarking has a goal of hiding the owner’s visual information in the source visual information. The purpose of digital watermarking is different from other techniques, such as , where the goal is to hide information in the source visual information in such a way that the information is not possible to detect.
Watermarking is a technique for the insertion of side information, defined by the information’s owner, into the source (cover) information. It is widely utilized in image/video applications.
The 14th IWDW, International Workshop on Digital-forensics and Watermarking (IWDW 2015) is a premier forum for researchers and practitioners working on novel research, development and applications of digital watermarking and forensics techniques for multimedia security. We invite submissions of high-quality original research papers. Each submitted paper will be reviewed by at least two reviewers. Two prizes are to be awarded for the best paper and the best student paper, respectively. The proceedings of IWDW 2015 will be published as the Lecture Notes in Computer Science (LNCS) by Springer.