ABSTRACT
Computerised image processing techniques are playing a growing role in manipulating these images in order to aid in the clinical decision-making process. This chapter focuses on two fields: image filtering and image segmentation. Image filtering techniques can be broken down into spatial domain operations and frequency domain operations. Spatial domain operations can be further broken down into point-processing and mask-processing operations. Both produce a new version of the original image; the difference lies in which pixel/voxel intensities are used to determine the new intensity at any given point. As well as performing image filtering operations in the spatial domain, similar operations can be performed in the frequency domain. Frequency domain representations of one-dimensional signals are based on the fact that any signal can be expressed as a weighted sum of sine waves of different frequencies and phases. In reality, many segmentation problems are challenging than this and a more complex series of operations may be required to produce satisfactory segmentations.
