Not even close. Even using two orthogonal projections directly, rather than just the summary statistic of area or perimeter, doesn't uniquely determine volume. If you had three orthogonal projections you could begin to produce a rough approximation of the volume, for example by discretization using the intersections of the pixels to determine the voxels occupied. This still wouldn't account for any concavities or hollows in the object, which could be significant depending upon the application (e.g. in estimating the volume of a bell this way you could be off by orders of magnitude), or fine scale structure of the object. Three projections is hardly the magic number either. Imagine your object was a sphere, if you took three orthographic projections of the sphere they would all be circles. If you pasted these circles on rectangular solid (e.g. block of wood) and cut them out in turn (e.g. with a band saw), what you would get would hardly be a polished sphere. Also, photos are not orthographic projections, so even after accounting for lens distortion your pixels define pyramidal sections in space, not rectangles, so their intersection defines complicated 3d polygons rather than simple rectagular voxels.
Best of luck, - Mike On Sun, 22 Jul 2007, A. Rabatsky wrote: > I'd like to know how to calculate volume using 2 measures of either area > or perimeter. I have 2 digital photographs, one provides a top view and > one provides a side view, of the object that I want to calculate the > volume of. I need to know if there's a mathematical formula that I can > plug in area from the top view & area from the side view to get volume. I > can add photos later if need be. > > Thanks. > ____________________________________________________________ [EMAIL PROTECTED] Program in Ecology http://www.duke.edu/~mcd7/lab Dept. of Biology lab: (919) 660-7295 Duke University home: (919) 401-6594 Durham, NC 27708
