1. A method of assessing breast density for breast cancer risk applications, comprising: receiving digital image data including a plurality of pixels; calibrating the digital image data; measuring a variation of pixel values of the calibrated digital image data, wherein measuring a variation of pixel values of the calibrated digital image data further comprises at least one of calculating an l 2 norm or order derived therefrom or calculating an l 1 norm or order derived therefrom; and associating the variation of pixel values with a measure of risk for breast cancer, wherein the variation of pixel values correlates with at least one of a relative risk for breast cancer, an odds ratio for breast cancer, or an absolute risk prediction for breast cancer.