US Patent 8130302 Methods and apparatus providing selective binning of pixel circuits

A pixel circuit configured for optionally connecting the floating diffusion region of the pixel circuit to a floating diffusion region of another pixel circuit. Methods of using the pixel circuit include averaging or summing multiple photosensor outputs in the combined floating diffusion regions, varying the conversion gain of a pixel circuit floating diffusion region, and utilizing multiple readout circuits to readout charges transferred from a single photosensor to the combined floating diffusion regions. A method of window-of-interest averaging that utilizes the combined floating diffusion regions is also disclosed.