In one aspect, a sensor includes an image acquisition controller and a pixel array. The pixel array includes a first set of pixels electrically coupled to the controller and a second set of pixels electrically coupled to the controller. The sensor is configured to operate in a first mode and a second mode. When operating in the first mode, the controller is configured to acquire signals from only the first set of pixels for generating a low-resolution image. When operating in the second mode, the controller is configured to acquire signals from both the first set of pixels and the second set of pixels for generating a high-resolution image.