Print Email Facebook Twitter Asymmetric perceptual confounds between canonical lightings and materials Title Asymmetric perceptual confounds between canonical lightings and materials Author Zhang, F. (TU Delft Human Information Communication Design) de Ridder, H. (TU Delft Human Information Communication Design) Pont, S.C. (TU Delft Human Information Communication Design) Date 2018 Abstract To better understand the interactions between material perception and light perception, we further developed our material probe MatMix 1.0 into MixIM 1.0, which allows optical mixing of canonical lighting modes. We selected three canonical lighting modes (ambient, focus, and brilliance) and created scenes to represent the three illuminations. Together with four canonical material modes (matte, velvety, specular, glittery), this resulted in 12 basis images (the "bird set"). These images were optically mixed in our probing method. Three experiments were conducted with different groups of observers. In Experiment 1, observers were instructed to manipulate MixIM 1.0 and match optically mixed lighting modes while discounting the materials. In Experiment 2, observers were shown a pair of stimuli and instructed to simultaneously judge whether the materials and lightings were the same or different in a four-category discrimination task. In Experiment 3, observers performed both the matching and discrimination tasks in which only the ambient and focus light were implemented. Overall, the matching and discrimination results were comparable as (a) robust asymmetric perceptual confounds were found and confirmed in both types of tasks, (b) performances were consistent and all above chance levels, and (c) observers had higher sensitivities to our canonical materials than to our canonical lightings. The latter result may be explained in terms of a generic insensitivity for naturally occurring variations in light conditions. Our findings suggest that midlevel image features are more robust across different materials than across different lightings and, thus, more diagnostic for materials than for lightings, causing the asymmetric perceptual confounds. Subject OA-Fund TU Delft To reference this document use: http://resolver.tudelft.nl/uuid:c1670e03-92a7-48c1-9770-98c8ad38df69 DOI https://doi.org/10.1167/18.11.11 ISSN 1534-7362 Source Journal of vision, 18 (11), 1-19 Part of collection Institutional Repository Document type journal article Rights © 2018 F. Zhang, H. de Ridder, S.C. Pont Files PDF i1534_7362_18_11_11.pdf 1.33 MB Close viewer /islandora/object/uuid:c1670e03-92a7-48c1-9770-98c8ad38df69/datastream/OBJ/view