Study on mathematical model for true gray level of X-ray-scanning images of object

Discussed the problem of how to get the true gray levels of ob je ct in the field of recognizing overlapped X- ray- scan imaged objects. Explain ed with pictures the way to simplify the problem of get true gray levels in the condition of n- object- overlapped into the problem of get true gray levels of two overlapped objects; Built the model for image of overlapped objects, then g et a fixed relationship between the true grayscale of two single objects and the grayscale of the transmission image when they lap over each other; Measured the reference aL in low- energy image through the step wedge experiments.