Texture refers to properties that represent the surface or structure of an object (in
re?ective or transmissive images, respectively); it is widely used, and perhaps intuitively
obvious, but has no precise de?nition due to its wide variability.Texture consists of texture primitives or texture elements, sometimes called texels.The ?rst corresponds to textile checks or
knitted stripes, and the second to the ?ner texture of the fabric or individual stitches.Texture is usually described as ?ne, coarse, grained, smooth, etc., implying
that some more precise features must be de?ned to make machine recognition possible.A texture
primitive is a contiguous set of pixels with some tonal and/or regional property, and
can be described by its average intensity, maximum or minimum intensity, size, shape,
etc.It is di?cult, however, to de?ne primitives for the checkered textile or fabric, which can
be de?ned by at least two hierarchical levels.Examples are shown in Figure 15.1; dog fur, grass, river pebbles, cork,
checkered textile, and knitted fabric.The main aim of texture analysis is recognition and texture-based shape analysis.