The generation of a digital X ray image is such a complex process which includes the production

the conversion and the transform of the X ray information. Generally

the interactions between X ray and other material include photoelectric absorption and comptom scattering

which have relations to the material's mass

density

equivalently atomic weight and the energy of X ray. In clinical use

X ray has a wide spectrum similar to the daylight

so its intensity will become harder and harder with different rate during it penetrates other material. Such nonlinearity and other stochastic noise will make a digital X ray image has no exact physical means. Due to the physical comparability

we use aluminium and lucite to simulate bone and software respectively

and image them under each kind of material thickness

then we can obtain an ideal image model use part of these data

which can be used to calibrate and linearize the X ray image. This method will be advantageous to the quantitative analysis of the human's physiological parameters such as the cardiac configuration

the blood flow

and the density of the contrast media in DSA.