Reflectance values for image-based relighting are often estimated from grouped pixels with similar reflectance, but such groupings are difficult to compute with certainty for sparse image data. To address this problem, we propose an iterative method that aggregates BRDF data in a single image with known geometry and lighting by soft grouping, where pixels contribute to one another’s estimate ac...

Porous silicon samples were prepared by electrochemical etching method for different etching times. The structural properties of porous silicon (PS) samples were determined from the Atomic Force Microscopy (AFM) measurements. The surface mean root square roughness (σ rms) changes as function of porosity were studied, and the influence of etching time on porosity and roughness was studied too. U...

Iterative least-squares estimation requires acciirate reflectance models to retrieve geometrical pammeters of curved surface elements from an image projection. W e investigate the use of .separating the diffuse (body) reflection from the specular (surface) reflection being re8ponsible for image highlights. Experzments show that the (smooth) daffuse component yields the best convergence properti...

Recognition systems have generally treated specular highlights as noise. We show how to use these highlights as a positive source of information that improves recognition of shiny objects. This also enables us to recognize very challenging shiny transparent objects, such as wine glasses. Specifically, we show how to find highlights that are consistent with an hypothesized pose of an object of k...

Title of Document: ENHANCEMENT OF A CANOPY REFLECTANCE MODEL FOR UNDERSTANDING THE SPECULAR AND SPECTRAL EFFECTS OF AN AQUATIC BACKGROUND IN AN INUNDATED TIDAL MARSH Kevin Ross Turpie, Ph.D., 2012 Directed By: Professor Michael Kearney, Department of Geographical Sciences The presence of water produces unique specular and spectral characteristics in an inundated tidal marsh canopy. The aquatic ...

A glossy highlight, viewed stereoscopically, can provide information about surface shape. For example, highlights appear to lie behind convex surfaces but in front of concave ones. A highlight is a distorted, reflected image of a light source. A ray equation is developed to predict the stereo disparities generated when a point source of light is reflected in a smooth, curved surface. This equat...

Retinal images are produced by interactions between a surface's 3D shape, material properties, and surrounding light field. In order to recover the 3D geometry of a surface, the visual system must somehow separate aspects of image structure generated by a surface's shape from structure generated by its material properties or the light field in which it is embedded. Attributing image structure t...