Planar digital image sensors facilitate broad applications in a wide range of areas and the number of pixels has scaled up rapidly in recent years. However, the practical performance of imaging systems is fundamentally limited by spatially nonuniform optical aberrations originating from imperfect lenses or environmental disturbances. We propose an integrated scanning light-field imaging sensor, termed unstructured meta-imaging sensor, to achieve high-performance photography up to a gigapixel with a single spherical lens without a data prior, leading to orders-of-magnitude reductions in system capacity and costs for optical imaging. Moreover, high-density accurate depth maps can be retrieved simultaneously, facilitating diverse applications from autonomous driving to industrial inspections.