It has long been recognized that a convincing pictorial representation of an object can sometimes be achieved by drawing just a few salient contours in an image. This phenomenon is really quite remarkable, given that a line drawing effectively strips away almost all of the variations in color and shading that are ordinarily available in natural scenes. Somehow the artists who create such drawings are able to capture the essential information for perceptual recognition with just a few simple strokes. Although a well structured line drawing is easily interpreted by human observers, the ability to create these drawings can require considerable artistic skill. Indeed, despite almost a half century of research in the field of computer vision, there are no existing algorithms that can duplicate the performance of a competent human artist. In this project, Dr. James Todd and his students at the Ohio State University will investigate how human observers perceptually identify different types of image contours, such as shadows, corners or occlusion. The group will also examine which contours in an image are perceptually most important for creating pictorial representations of objects. The stimuli in these studies will include drawings by artists with varying amounts of training, who will be asked to produce line drawings of objects with known 3D structures. The drawings will be ranked by human observers to assess their relative perceptual effectiveness. The contours in the drawings will also be compared with different aspects of the depicted surface geometry in order to determine which specific aspects of a surface are most important for its pictorial depiction.
A better understanding of how human observers perceptually determine the 3D shapes of surfaces from 2D image data has many possible applications, including the design of more robust and effective algorithms in machine vision, improved techniques for 3D visualization in computer graphics and design, and the potential development of more functional prosthetic devices for the blind. This work may also have a significant impact on how students are taught to draw in art or design courses.
