Does Color Influence Image Complexity Perception?

In this paper we investigate if color influences the perception of image complexity. To this end we perform two different types of psycho-physical experiments on color and grayscale images. In the first experiment, images are ranked based on their complexity (image ranking), while in the second experiment the complexity of each image is assessed on a continuous scale (image scaling). Moreover, we investigate if ten image features, that measure colors as well as other spatial properties of the images, correlate with the collected subjective data. The performance of these correlations are evaluated in terms of Pearson correlation coefficients and Spearman rank-order correlation coefficients. We observe that for each type of experiment, subjective scores for color images are highly correlated with those of the corresponding grayscale versions suggesting that color is not a relevant attribute in evaluating image complexity. Moreover none of the tested simple image features seem to be adapt to predict the image complexity according to the human judgments.