1. A method for detecting motion of an entity equipped with a sensor capturing a sequence of images to be processed, the method comprising the following steps: determining a temporary motion vector relating to a current image as a function of reference data comprising a preceding image and a motion vector associated with the preceding image; when the temporary motion vector relating to the current image does not satisfy a reliability criterion, determining a temporary motion vector relating to a following image, on the basis of the same reference data; and when the temporary motion vector relating to the current image satisfies the reliability criteria, associating the temporary motion vector with the current image.