A global shutter image sensor includes an array of pixel groups arranged in rows and columns, each pixel group including four pixels and a shared readout circuit having a floating diffusion. Each pixel includes a photodiode, a transfer gate and a charge coupled gate (CCG) device. The CCG devices are coupled in series with the floating diffusion of the shared readout circuit. Control circuitry controls the image sensor such that all of the pixels simultaneously capture image information (charges) and then transfer the captured charges to the CCG devices during a global shutter operation. The control circuit then controls the CCG devices to act as a shift register that transfers the captured charges to the floating diffusion during sequential correlated double sampling readout phases. The readout circuit includes a shared reset transistor, a source-follower and row select transistor, and each pixel group is controlled by eight or fewer control signals.