How do different object properties combine for the purposes of object identification? We developed a paradigm that allows us measure the degree to which human observers rely on one object property (e.g., color) vs. another (e.g., material) when they make forced-choice similarity judgments. On each trial of our experiment, observers viewed a target object paired with two test objects: a material match, that differed from the target only in color (along a green-blue axis) and a color match, that differed from the target only in material (along a glossy-matte axis). Across trials, the target was paired with different combinations of material-match and color-match tests and observers selected the test that appeared more similar to the target. To analyze observer responses, we developed a model (a two-dimensional generalization of the maximum-likelihood difference scaling method) that allows us to recover (1) the color-material weight, reflecting the relative importance of color vs. material in object identification and (2) the underlying positions of the material-match and color-match tests in a perceptual color-material space. Our results reveal large individual differences in the relative weighting of color vs. material.
Ana Radonjić, Nicolas P. Cottaris, David H. Brainard, "Quantifying how humans trade off color and material in object identification" in Proc. IS&T Int’l. Symp. on Electronic Imaging: Human Vision and Electronic Imaging, 2018, pp 1 - 6, https://doi.org/10.2352/ISSN.2470-1173.2018.14.HVEI-516