SCECam: a spherical compound eye camera for fast location and recognition of objects at a large field of view

Abstract

In recent years, the compound eye imaging system has attracted great attention due to its fascinating optical features such as large field of view (FOV), small volume and high acuity to moving objects. However, it is still a big challenge to fabricate such a whole system due to the mismatch between the spherical compound eye imaging element and the planar imaging sensor. In this work, we demonstrate a kind of hemispherical compound eye camera (SCECam) which analogs the eye of the fruit fly. The SCECam consists of three sub-systems, a hemispherical compound eye, an optical relay system and a commercial CMOS imaging sensor. By introducing an intermediate optical relay system, the curved focal plane after the compound eye can be transformed and projected onto the planar focal plane of the imaging sensor. In this way, the SCECam can realize a large FOV (up to 122.4°) with 4400 ommatidia, which makes it possible to detect and locate fast moving objects at a very fast speed. It is calculated that the recognition speed of the SCECam is two to three orders of magnitude higher than those conventional methods such as the Canny and Log edge-detection methods.