Image Processing Reference
In-Depth Information
Chapter 2
Current State of the Art
This chapter presents past research efforts in the subject area related to this mono-
graph. An extensive study of the existing literature which forms the guidelines for
the development of new methodologies discussed in the monograph has been per-
formed. We begin with the definition of the process of fusion and discuss some of
the nomenclature in the field. We familiarize the reader with an overview of various
techniques of fusion. The purpose of this chapter is to make the readers aware of
various methodologies used for fusion, although not necessarily for remote sensing
applications alone. Then we explain various existing solutions for visualization of
hyperspectral data. With many techniques being developed, the problem of quan-
titative assessment of them is also gaining importance. This chapter also explores
the existing measures for an objective assessment of fusion techniques. An overview
of some of the evaluation techniques for fusion of hyperspectral data has also been
provided. At the end of this chapter, we describe the notations used in the subsequent
chapters of this monograph.
2.1 Introduction
During the past century, we have witnessed a rapid growth in the advancement of
technology. Invention of a large number of sensors has resulted in high volumes
of data collection. These datasets, obtained from multiple and multimodal sensors
provide complementary information about the scene or objects being imaged. The
performance of many intelligent systems and devices has significantly improved with
the availability of the multi-sensor input. However, instead of processing individual
inputs from all the sensors, it would be desirable to extract and merge the useful
information from the set of sensors, and process this selective information in order
to achieve a higher throughput. The usefulness of the information is, of course,
dependent on the final application it is being used for. Therefore, to use the high
amount of data in an effective manner, and to obtain a better performance from the
