For successful and accurate image analysis,
defining object primitives of suitable size and
shape is of utmost importance. As a rule of
thumb, good object primitives are as large as
possible, yet small enough to be used as
building blocks for the objects to be detected
in the image. Pixel is the smallest possible building block of an image, however it has
mixture of information. To get larger building
blocks, different segmentation methods are
available to form contiguous clusters of pixels
that have larger property space.