Biomedical Imaging

2Digital image processing

Before turning to physical and algorithmic principles of biomedical imaging in particular, we first consider images and image processing from a very general point of view. The scope of the present chapter is to provide definitions and preliminaries of image representation and processing. We define an image as a discretely sampled version of a physical observable f(x, y), defined over some domain⊂ ℝ2, the field of view (FOV). In most cases, the image represents a scalar real-valued function f(x, y) ∈ ℝ, e.g., the x-ray attenuation coefficient, the proton density, the concentration of some radioactive element or the ultrasound impedance, etc. In other cases, we may have f(x, y) ∈ ℂ; consider, for example, a quasi-monochromatic ...