Abstract: A methodology and apparatus is described that registers images outputted by at least two video camera sensors that are not necessarily bore-sighted nor co-located together. Preferably this can be performed in real-time at least at video rate. The two video camera sensors can be either of similar or two different modalities (e.g., one can be intensified visible, while the other can be thermal infrared) each possibly with a different field-of-view. The methodology and apparatus take advantage of a combination of Inertial Measurement Units (IMUs) information and image registration between the two camera sensors from computational image processing. In one preferred embodiment, the system uses a rifle mounted weapon sight camera sensor and a helmet mounted sensor camera. The aim point of the weapon sight camera sensor (e.g., typically at the image center) zeroed to the true rifle aim point is digitally overlayed as a reticle on the video image from the helmet sensor, displayed on a head mounted display (HMD).