ABSTRACT
The term resolution refers to the smallest measurable physical quantity. The resolution of an imaging system is defined as the ability of the system to record finer details in a distinguishable manner [2]. The term image resolution can be defined as the smallest measurable detail in a visual presentation. In image processing, it is a measure of the amount of detail provided by an image or a video signal. The term image resolution is classified into different types: spatial resolution, brightness resolution, spectral resolution, and temporal resolution. In this chapter we address the problem of increasing the spatial resolution of given low spatial resolution images. A digital image is represented using a set of picture elements. These picture elements are called “pixels” or “pels.” A pixel at any location in an image carries the information regarding the image intensity at that location in the image. An image represented using a large number of pixels conveys more information as compared to the same image when represented using fewer pixels. Spatial resolution refers to the spacing of the pixels in an image and is measured in pixels per inch (ppi). High spatial resolution allows for sharp details and fine-intensity transitions across all directions. The representation of an image having sharp edges and subtle intensity transition by less dense pixels gives rise to blocky effects. On the other hand, the images with a dense set of pixels
gives the viewer the perception of finer details and offers a pleasing view. In the rest of this chapter, the term resolution is explicitly used to refer to spatial resolution unless specified otherwise.
