1. A method comprising: using at least one processing device: obtaining a multi-dimensional image of a surface having a texture; identifying multiple discrete auto-covariance functions of the multi-dimensional image, each discrete auto-covariance function identified using a different set of pixels in the multi-dimensional image; averaging the multiple discrete auto-covariance functions to generate a final discrete auto-covariance function of the multi-dimensional image; and identifying a dominant size of the texture using the final discrete auto-covariance function.