An image sensor suitable for use in an augmented reality system to provide low latency image analysis with low power consumption. The augmented reality system can be compact, and may be small enough to be packaged within a wearable device such as a set of goggles or mounted on a frame resembling ordinary eyeglasses. The image sensor may receive information about a region of an imaging array associated with a movable object and selectively output imaging information for that region. The region may be updated dynamically as the image sensor and/or the object moves. Such an image sensor provides a small amount of data from which object information used in rendering an augmented reality scene can be developed. The amount of data may be further reduced by configuring the image sensor to output indications of pixels for which the measured intensity of incident light changes.