Photometric Approaches to Three-dimensional Scene Reconstruction

Abstract

In contrast to geometric methods, photometric approaches to three-dimensional scene reconstruction exploit the pixel intensities in the image to recover the shape of a surface or an object. Shadows in multiple images of a surface acquired under different illumination conditions may contain a significant amount of information about the surface shape (shape from shadow, cf. Section 2.1). The pixel intensities can be used to determine the position-dependent surface orientation, which by integration yields a depth map of the surface (shape from shading, cf. Section 2.2). Making use of the intensity information contained in multiple images leads to the photometric stereo approach described in Section 2.3. Utilising the polarisation state of light reflected from the surface instead of its intensity under certain circumstances allows a more accurate determination of surface orientation (shape from polarisation, Section 2.4).