Context effects on the perception of saturation of fruit colors in still-life paintings.

Still-life painters, especially of the so-called Golden Age (17th century) in the Netherlands, are famous for their masterful techniques of rendering reality. Their amazing abilities to depict different material properties of fruits and flowers are stunning. But how important are these careful arrangements of different objects for the perception of an individual item? Is the perceived color saturation of a single fruit influenced by its surrounding context? We selected fruits in still-life paintings as stimuli to investigate whether and how perceived saturations of fruits were affected by their original contexts. In our study, we focused especially on effects of five context properties: complementary colors, chromatic and luminance contrast, object overlap, and surround variance. Six fruit varieties depicted in high-quality digital reproductions of 48 classic and eight varieties in 64 more recent, modern still-life paintings were selected. In a single trial, eight images of fruits of the same variety appeared on a neutral gray background; half were single fruit cutouts, and the other half were the same fruits embedded in their circular contexts. Fifteen participants ranked all eight images according to perceived color saturations of the fruits. Saturation ratings showed a high agreement of 77%. Surrounding contexts led to an increase in perceived saturation of central fruits. This effect was mainly driven by object overlap, the presence of the central fruit type also in the context, and surround variance. Chroma contrast between fruits and contexts decreased saturation significantly. No significant context effects were found for complementary colors or luminance contrast. Our results show that in paintings, many of the cues that are usually experimentally isolated occur in interesting combinations and lead to an increase in perceived saturation that makes fruit objects more appealing and convincing.