In a previous study we investigated the roughness of real world textures taken from the CUReT database. We showed that people could systematically judge the subjective roughness of these textures. However, we did not determine which objective factors relate to these perceptual judgments of roughness. In the present study we take the first step in this direction using a subband decomposition of the CUReT textures. This subband decomposition is used to predict the subjective roughness judgments of the previous study. We also generated synthetic textures with uniformly distributed white noise of the same variance in each subband, and conducted a perceptual experiment to determine the perceived roughness of both the original and synthesized texture images. The participants were asked to rank-order the images based on the degree of perceived roughness. It was found that the synthesis method produces images that are similar in roughness to the original ones except for a small but systematic deviation.