Real or Fake ?

Abstract

While efforts to create realistic images have generated break-throughs in computer graphics modeling, there has been little research to date on factors causing people to perceive images as real versus computer-generated (CG). The motivation of the current experiment is to begin investigating such factors. We showed both computer-graphics experts and laypersons real photos and CG images. Photo and CG images were of three types: original, modified to show only intrinsic reflectance components, and modified to show only intrinsic shading components (grayscale). Participants judged whether each image was a real photo or a CG image. Results showed that visual realism depends not only on image properties, but also on cognitive characteristics of viewers. Shading was especially crucial for visual realism. Color was also important. Experts outperformed laypersons, but their advantage was limited to grayscale images. This research at the interface between human cognition and computer vision is a starting point for investigating the factors underlying visual realism.