IMAGE SENSOR WITH MULTI-GAIN READOUT

An image sensor may include an array of image pixels. The array of image pixel may be coupled to control circuitry and readout circuitry. One or more image pixels in the array may each include a photodiode and a floating diffusion region. The floating diffusion region may be coupled to a charge storage structure for a low conversion gain configuration and can be coupled to a charge storage structure for a medium conversion gain configuration. The medium conversion gain charge storage structure may be activated when transferring photodiode charge to the floating diffusion region for a high conversion gain configuration. The control circuitry may control each pixel to perform a high conversion gain readout operation, a medium conversion gain readout operation, and a low conversion gain readout operation. If desired, the medium conversion gain readout operation may be omitted.