The human visual system observes and understands a scene/image by making a series of fixations. Every "fixation point" lies inside a particular region of arbitrary shape and size in the scene which can either be an object or just a part of it. We define as a basic segmentation problem the task of segmenting that region containing the "fixation point". Segmenting this region is equivalent to finding the enclosing contour
Ajay K. Mishra, Yiannis Aloimonos, Loong Fah Cheon