Showing papers on "Perspective (geometry) published in 1974"

Validation of a mathematical model for correction of photographic perspective error

Abstract: Photographic perspective error long has plagued the researcher attempting to obtain accurate three-dimensional coordinates from two-dimensional film. Accurate velocity and acceleration values are dependent on accurate positional information, and photographic perspective error is responsible for the concealment of true three-dimensional position coordinates. The purpose of this investigation was the validation of mathematical formulas derived to correct for photographic perspective error. These corrective formulas were derived from trigonometric relationships between two two-dimensional, perpendicular views of any th te-dimensional position in space and were designed to transform measured coordinate information (from film) to true three-dimensional coordinate data. The corrective formula for any point P is: where x = true x value; y = true y value; z = true z value; XYx = x coordinate measured in XY film plane; Zyy = y coordinate measured in ZY film plane; Zyz = z coordinate measured in ZY film plane; Dx = distance from Film Plane 2 to origin along x axis; and Dz = distance from Film Plane 1 to origin along z axis. A review of related literature on the topic of perspective error and the derivation of the corrective formula utilized in this investigation can be found in Martin and Pongratz (1973) or obtained from the senior author.

A Computer Program for Drawing Non- Classical Perspectives

Abstract: This article deals with a new way of portraying a three- dimensional object on a two-dimensional plane surface. In classical perspective each point of an object or scene is projected upon a plane by means of a bundle of straight projection rays departing from a unique point or point of view. The author proposes a similar procedure except that the straight projection rays of classical perspective are replaced with special curved ones