1. A method, comprising: enhancing a contrast to noise ratio (CNR) of image data, generating CNR enhanced image data, wherein the CNR enhanced image data has a substantially same image quality as the image data, the enhancing including: determining a piece wise approximation of the image data; determining a bone mask based on the image data: determining a contrast media map based on the piece wise approximation and the bone mask: determining an enhanced contrast media map based on the contrast media map and one or more parameters; determining data complementary to the piece wise approximation of the image data based on the image data and the piece wise approximation; and determining the CNR enhanced image data based on the enhanced contrast media map and the data complementary to the piece wise approximation.