1. A method of operating mobile floor cleaning robot, the method comprising: receiving, at a controller, a sequence of images of a floor surface from an imaging sensor in communication with the controller, each image having an array of pixels; for each image, segmenting the image into color blobs, using the controller, by: color quantizing pixels of the image; determining a spatial distribution of each color of the image based on corresponding pixel locations; and for each image color, identifying areas of the image having a threshold spatial distribution for that color; tracking, using the controller, a location of each color blob with respect to the imaging sensor across the sequence of images; identifying, using the controller, a location of an object on a floor surface away from the robot; issuing a first drive command from the controller to a drive system of the robot to drive the robot across the floor surface to clean the floor surface at the identified location of the object; determining, using the controller, whether the object persists on the floor surface; and when the object persists, issuing a second drive command from the controller to the drive system to drive the robot across the floor surface to re-clean the floor surface at the identified location of the object.