HEMISPHERICAL PHOTOGRAPHS USED FOR MAPPING CONFINED SPACES

This paper presents two methods for using fisheye photographs for mapp ing confined areas. The first approach is intended for relatively flat objects, observed at very close range, and consists of producing a re ctified view from a fisheye photograph. After scanning and correcting the spherical distortions present in the original image, a simple proj ective transformation creates a constant scale image from which two-di mensional (2D) data can be extracted. The second method aims at recove ring three-dimensional data from two stereo fisheye photographs. This method also involves the same image correction for spherical distortio ns, but the two resulting perspective images are afterwards analyzed u tilizing stereovision in a digital photogrammetric workstation. Practi cal experiments, conducted with a 35-mm camera equipped with a fisheye lens, demonstrate the applicability and feasibility of the two softco py photogrammetry methods in the context of mapping electric distribut ion wells.