One example image sensor includes a metasurface, a substrate, and an optical-to-electrical converter. Arrays in the metasurface are arranged on the top of the substrate. The metasurface includes multiple subunits. Each subunit includes an array including multiple columnar structures. The bottom of the substrate is disposed on a surface of the optical-to-electrical converter in the image sensor. The metasurface includes at least two media with different refractive indexes. The optical-to-electrical converter includes an array for optical-to-electrical conversion. The array of the optical-to-electrical converter is divided into multiple color regions. The metasurface is configured to refract incident light and transmit, through the substrate, refracted light to a corresponding color region in the array of the optical-to-electrical converter. In addition, each subunit refracts incident light and then transmits refracted light to a color region in a corresponding color unit.