Image sensors with dynamic pixel binning

A method for dynamic pixel binning comprising:

• enabling a first binning configuration in an image sensor system to establish a first pixel configuration using a first floating diffusion region, the first pixel configuration comprising a plurality of sensor elements;
• reading a first pixel value from the first floating diffusion region;
• enabling a second binning configuration in the image sensor system, the second binning configuration maintaining the first pixel configuration using a second floating diffusion region, the second floating diffusion region different from the first floating diffusion region;
• reading a second pixel value from the second floating diffusion region,
• comparing the first and second pixel values, and
• outputting a comparison signal indicating a result of the comparing.

An image sensor system, comprising:

• a two-dimensional array of pixel elements;
• a plurality of floating diffusion regions, each floating diffusion region corresponding to different one of the pixel elements, each floating diffusion region configured to be individually and selectively enabled;
• a plurality of comparison circuits, each comparison circuit coupled to an output of two floating diffusion regions, wherein no floating diffusion region is coupled to two comparison circuits, each of the comparison circuits configured to:
• receive input signals from the respective two floating diffusion regions,
• compare the input signals, and
• output a comparison signal based on the comparison of the input signals.

A method of detecting motion in an image sensing system, the method comprising:

• transmitting a first enable signal to an image sensor system during a first frame period, the image sensor system comprising:
• a two-dimensional array of pixel elements;
• a plurality of floating diffusion regions, each floating diffusion region corresponding to different one of the pixel elements, each floating diffusion region configured to be individually and selectively enabled;
• a plurality of comparison circuits, each comparison circuit coupled to an output of two floating diffusion regions, wherein no floating diffusion region is coupled to two comparison circuits, each of the comparison circuits configured to receive input signals from the respective two floating diffusion regions, compare the input signals, and output a comparison signal based on the comparison of the input signals;
• the first enable signal configured to enable a first group of floating diffusion regions;
• transmitting a second enable signal to the image sensor system during a second frame period, the second enable configured to enable a second group of floating diffusion regions, the floating diffusion regions of the second group of floating diffusion regions different from the floating diffusion regions of the first group of floating diffusion regions;
• receive a sensor signal from the image sensor system, the sensor signal comprising comparison values based on the comparison signals;
• and
• detecting motion based on the sensor signal.