1. A system for detecting a movement of an object marked with a marker, comprising: a sensor configured to capture a first image of the marker and to capture a second image of the marker after the first image, each of the first and second images comprising pixels each having a visual intensity; and a controller coupled to the sensor and configured to: compare the first image and the second image by comparing the visual intensity of each of the pixels of the first image with the visual intensity of each of the pixels of the second image, determine an area of overlap between the first image and the second image based on the comparison, calculate a change in position of the marker in the second image relative to the marker in the first image based on the area of overlap, and detect the movement of the object based on the change in position of the marker.