1. A mobile camera system that connects plural camera apparatuses including at least first and second camera apparatuses mounted on a mobile body to one another and combines images photographed by the first and the second camera apparatuses, wherein reference data obtained by the first camera apparatus is transferred to the second camera apparatus via a camera control unit, signal processing is performed in the second camera apparatus on the basis of the reference data transferred to generate a corrected image, and an image from the first camera apparatus and the corrected image outputted from the second camera apparatus are combined to output a combined image.