Assessing Photorealism of Rendered Objects in Real-World Images: A Transparent and Reproducible User Study

Abstract: In an era where numerous studies claim to achieve almost photorealism with real-time automated environment capture, there is a need for assessments and reproducibility in this domain. This paper presents a transparent and reproducible user study aimed at evaluating the photorealism of real-world images composed with virtual rendered objects, that have been generated using classical environment capturing and rendering techniques. We adopted a two-alternative forced choice methodology to compare pairs of images created by integrating virtual objects into real photographs, following a classic pipeline. A control group with defined directional light parameters was included to validate the study's correctness. The findings revealed some insights, suggesting that observers experienced difficulties in differentiating between rendered and real objects. This work establishes the groundwork for future studies, aimed at enhancing the visual fidelity and realism of virtual objects in real-world environments.