1. A method of automatically determining a region of interest in hip scan data from a bone densitometer, comprising: computer-analyzing greyscale anterior-posterior projective image data of the hip of a patient taken with an x-ray bone densitometer to automatically, without necessitating user intervention, identify a global region that includes both soft tissue and bone and encompasses at least the femoral neck, trochanter and inter-trochanter portions of the patient's hip; computer-processing at least some of said image data to the extent related to the global region to identify, without necessitating user intervention, one or more sub-regions of interest selected from the femoral neck, trochanter and the inter-trochanter; and further computer-processing at least some of the image data to the extent related to the identified one or more sub-regions to obtain one or more site-specific estimates of bone mineral density data for the identified sub-regions for use in assessing fracture risk.