In accordance with an embodiment of the present invention, an image sensor comprises a plurality of pixel sensing circuits. Each pixel sensing circuit includes a photodiode and a storage node. Each pixel sensing circuit further includes a first transistor coupled between the photodiode and the storage node and a second transistor coupled between the photodiode and a shared node. The shared node is coupled to the plurality of pixel sensing circuits. The image sensor may include a reset transistor and/or a read-out circuit coupled to the shared node.