Pixels in an array of image sensor pixels contain photo-sensors and circuits having inputs connected to the photosensors. The circuits have feedback loops for reducing fixed pattern noise in the array. Output from each pixel is used to latch a multibit counter value supplied by a global counter. Each feedback loop preferably includes a pair of alternately-toggling switching transistors to minimize unwanted charge injection. An image sensor according to the invention can be used for, e.g., motion sensing.