Date of Graduation
This document proposes a patent pending process, called 3D COLOR, to measure color and appearance of three-dimensional (3D), non-specifically oriented objects with a 24 bit color machine vision system. The core technology of 3D COLOR encompasses image correction and shading correction. A methodology is developed and implemented for improving image fidelity by calibrating and removing camera, illumination, and optical influences from the image. Techniques for removing the shape induced shading from the image data of a three-dimensional object are explored. This facilitates large region analysis of color and appearance for finished products and on-line color monitoring for nonplanar web processes for quality control. A prototype system is developed for on-line color analysis of extruded ABS plastic. Online test results are presented. System repeatability is less than 1 CIE (Commission Internationale de l'Eclairage) Î”E L*a*b*.
Preece, William K., "Three-dimensional color: Development of a machine vision colorimeter." (1994). Graduate Theses, Dissertations, and Problem Reports. 9598.