1. A method of processing an x-ray image, at least part of the method implemented using a processor, the method comprising: obtaining a first x-ray image and a second x-ray image in a session, wherein the first and the second x-ray images are obtained using respective x-ray radiation having a same energy level, and at least a portion of the first x-ray image and at least a portion of the second x-ray image comprise respective images of a same portion of an object; determining a composite image based at least in part on the at least a portion of the first x-ray image and the at least a portion of the second x-ray image, wherein one of the first and second x-ray images is a real-time input for determining the composite image; and using the composite image to determine whether the object has moved; and at least one of storing the composite image in a medium, displaying the composite image, and adjusting a system component based at least in part on the composite image.