Reconstructing Geometry from Its Latent Structures

Our world is full of objects with complex shapes and structures. Through extensive experience humans quickly develop an intuition about how objects are shaped, and what their material properties are simply by analyzing their appearance. We engage this intuitive understanding of geometry in nearly everything we do.It is not surprising then, that a careful treatment of geometry stands to give machines a powerful advantage in the many tasks of visual perception. To that end, this thesis focuses on geometry recovery in a wide range of real-world problems. First, we describe a new approach to image registration. We observe that the structure of the imaged subject becomes embedded in the image intensities. By minimizing the change in shape of these intensity structures we ensure a physically realizable deformation. We then describe a method for reassembling fragmented, thin-shelled objects from range-images of their fragments using only the geometric and photometric structure embedded in the boundary of each fragment. Third, we describe a method for recovering and representing the shape of a geometric texture (such as bark, or sandpaper) by studying the characteristic properties of texture---self similarity and scale variability. Finally, we describe two methods for recovering the 3D geometry and reflectance properties of an object from images taken under natural illumination. We note that the structure of the surrounding environment, modulated by the reflectance, becomes embedded in the appearance of the object giving strong clues about the object's shape.Though these domains are quite diverse, an essential premise---that observations of objects contain within them salient clues about the object's structure---enables new and powerful approaches. For each problem we begin by investigating what these clues are.We then derive models and methods to canonically represent these clues and enable their full exploitation. The wide-ranging success of each method shows the importance of our carefully formulated observations about geometry, and the fundamental role geometry plays in visual perception.Ph.D., Computer Science -- Drexel University, 201

Public Archaeology Via Skyscraper: Outcome and Experience

A recent archaeology awareness campaign projected Public Service Announcements from the top of a city skyscraper. These 30-second videos featured animated 3D artifact reconstructions alongside an archaeology-themed message. This was not just public archaeology done in an unusual way but public archaeology conducted toward an unusually broad end: the processes involved in creating the PSAs served many masters, not just archaeology’s needs. This paper reports on this reflexive, dialogic, public archaeology case study where communities make use of the past for their own needs in the present

Public Archaeology Via Skyscraper: Outcome and Experience

A recent archaeology awareness campaign projected Public Service Announcements from the top of a city skyscraper. These 30-second videos featured animated 3D artifact reconstructions alongside an archaeology-themed message. This was not just public archaeology done in an unusual way but public archaeology conducted toward an unusually broad end: the processes involved in creating the PSAs served many masters, not just archaeology’s needs. This paper reports on this reflexive, dialogic, public archaeology case study where communities make use of the past for their own needs in the present