Signal Processing at Your Fingertips!

Let us flash back to the 1970s when the editors-in-chief of this e-reference were graduate students. One of the time-honored traditions then was to visit the libraries several times a week to keep track of the latest research findings. After your advisor and teachers, the librarians were your best friends. We visited the engineering and mathematics libraries of our Universities every Friday afternoon and poured over the IEEE Transactions, Annals of Statistics, the Journal of Royal Statistical Society, Biometrika, and other journals so that we could keep track of the recent results published in these journals. Another ritual that was part of these outings was to take sufficient number of coins so that papers of interest could be xeroxed. As there was no Internet, one would often request copies of reprints from authors by mailing postcards and most authors would oblige. Our generation maintained thick folders of hardcopies of papers. Prof. Azriel Rosenfeld (one of RC’s mentors) maintained a library of over 30,000 papers going back to the early 1950s!

Another fact to recall is that in the absence of Internet, research results were not so widely disseminated then and even if they were, there was a delay between when the results were published in technologically advanced western countries and when these results were known to scientists in third world countries. For example, till the late 1990s, scientists in US and most countries in Europe had a lead time of at least a year to 18 months since it took that much time for papers to appear in journals after submission. Add to this the time it took for the Transactions to go by surface mails to various libraries in the world. Scientists who lived and worked in the more prosperous countries were aware of the progress in their fields by visiting each other or attending conferences.

Let us race back to 21st century! We live and experience a world which is fast changing with rates unseen before in the human history. The era of Information and Knowledge societies had an impact on all aspects of our social as well as personal lives. In many ways, it has changed the way we experience and understand the world around us; that is, the way we learn. Such a change is much more obvious to the younger generation, which carries much less momentum from the past, compared to us, the older generation. A generation which has grew up in the Internet age, the age of Images and Video games, the age of IPAD and Kindle, the age of the fast exchange of information. These new technologies comprise a part of their “real” world, and Education and Learning can no more ignore this reality. Although many questions are still open for discussions among sociologists, one thing is certain. Electronic publishing and dissemination, embodying new technologies, is here to stay. This is the only way that effective pedagogic tools can be developed and used to assist the learning process from now on. Many kids in the early school or even preschool years have their own IPADs to access information in the Internet. When they grow up to study engineering, science, or medicine or law, we doubt if they ever will visit a library as they would by then expect all information to be available at their fingertips, literally!

Another consequence of this development is the leveling of the playing field. Many institutions in lesser developed countries could not afford to buy the IEEE Transactions and other journals of repute. Even if they did, given the time between submission and publication of papers in journals and the time it took for the Transactions to be sent over surface mails, scientists and engineers in lesser developed countries were behind by two years or so. Also, most libraries did not acquire the proceedings of conferences and so there was a huge gap in the awareness of what was going on in technologically advanced countries. The lucky few who could visit US and some countries in Europe were able to keep up with the progress in these countries. This has changed. Anyone with an Internet connection can request or download papers from the sites of scientists. Thus there is a leveling of the playing field which will lead to more scientist and engineers being groomed all over the world.

The aim of Online Reference for Signal Processing project is to implement such a vision. We all know that asking any of our students to search for information, the first step for him/her will be to click on the web and possibly in the Wikipedia. This was the inspiration for our project. To develop a site, related to the Signal Processing, where a selected set of reviewed articles will become available at a first “click.” However, these articles are fully refereed and written by experts in the respected topic. Moreover, the authors will have the “luxury” to update their articles regularly, so that to keep up with the advances that take place as time evolves. This will have a double benefit. Such articles, besides the more classical material, will also convey the most recent results providing the students/researchers with up-to-date information. In addition, the authors will have the chance of making their article a more “permanent” source of reference, that keeps up its freshness in spite of the passing time.

The other major advantage is that authors have the chance to provide, alongside their chapters, any multimedia tool in order to clarify concepts as well as to demonstrate more vividly the performance of various methods, in addition to the static figures and tables. Such tools can be updated at the author’s will, building upon previous experience and comments. We do hope that, in future editions, this aspect of this project will be further enriched and strengthened.

In the previously stated context, the Online Reference in Signal Processing provides a revolutionary way of accessing, updating and interacting with online content. In particular, the Online Reference will be a living, highly structured, and searchable peer-reviewed electronic reference in signal/image/video Processing and related applications, using existing books and newly commissioned content, which gives tutorial overviews of the latest technologies and research, key equations, algorithms, applications, standards, code, core principles, and links to key Elsevier journal articles and abstracts of non-Elsevier journals.

The audience of the Online Reference in Signal Processing is intended to include practicing engineers in signal/image processing and applications, researchers, PhD students, post Docs, consultants, and policy makers in governments. In particular, the readers can be benefited in the following needs:

The Signal Processing topics have been divided into a number of subtopics, which have also dictated the way the different articles have been compiled together. Each one of the subtopics has been coordinated by an AE (Associate Editor). In particular:

We would like to thank all the Associate Editors for all the time and effort in inviting authors as well as coordinating the reviewing process. The Associate Editors have also provided succinct summaries of their areas.

The articles included in the current editions comprise the first phase of the project. In the second phase, besides the updates of the current articles, more articles will be included to further enrich the existing number of topics. Also, we envisage that, in the future editions, besides the scientific articles we are going to be able to include articles of historical value. Signal Processing has now reached an age that its history has to be traced back and written.

Last but not least, we would like to thank all the authors for their effort to contribute in this new and exciting project. We earnestly hope that in the area of Signal Processing, this reference will help level the playing field by highlighting the research progress made in a timely and accessible manner to anyone who has access to the Internet. With this effort the next breakthrough advances may be coming from all around the world.The companion site for this work: http://booksite.elsevier.com/9780124166165 includes multimedia files (Video/Audio) and MATLAB codes for selected chapters.

Rama Chellappa

Sergios Theodoridis