Abstract
We report that a large field of view (FOV) retinal image can be acquired by a low-cost smart fundus camera. This handheld system includes a Raspberry Pi board, a touch screen display, a customized optical lens group, a ring LED light, and a Li-battery. Based on the open hardware platform and Linux operating system, we have integrated the portable system with component switching and image processing functions. Wide FOV has been realized using image stitching and structure from motion algorithms. This customized low-cost handheld fundus camera provides better image quality than cellphone-based fundus imaging solutions and offers more operational features than traditional portable fundus cameras. It may benefit field portable ophthalmic diagnostic applications.