Chapter 3 – View Extraction

Views are the fundamental elements of view-based 3-D object analysis and view extraction comprises the first step of this methodology. A group of carefully obtained views can provide a good foundation for further V3DOR. As a result, effective view acquisition techniques are highly desired for 3-D applications. There are generally three types of view extraction methods: dense sampling viewpoints, predefined camera arrays, and generated views. In the methods of dense sampling viewpoints, multiple views are captured from the densely sampled directions. In the second type of methods, multiple views can be collected by 2-D projections taken from canonical or noncanonical view directions and each projection is described by a 2-D image. Setting the camera array with view directions is the primary task related to view extraction. For the third type of methods, the view is generated from the 3-D object, as opposed to the direct graph or depth images. In this chapter, we introduce these three types of view extraction methods and discuss them in detail.