MANUFACTURING SECURITY DOCUMENTS USING 3D SURFACE PARAMETERIZATION AND HALFTONE DITHERING

摘要

In a method for manufacturing a security document, a three-dimensional surface model is mapped into a two-dimensional parameter space, thereby generating a color or brightness image in this parameter space. The image is rendered using halftone techniques and projected back, as a texture, onto the model, whereupon the model is applied to the document using three-dimensional projection. This technique allows to create a two- dimensional rendering of a three-dimensional textured object where the texture not only serves to emphasize the curvature and orientation of the object's surface, but also serves to encode the color or brightness of the same.