1. A video imager comprising: a first region equipped with light-sensitive cells for capturing images; and a second region having a plurality of unidirectional motion sensors adjacent to respective edges of the first region, enabling local motions to be measured on edges of the images simultaneously with the capture of the images, all of the unidirectional motion sensors in the second region having a detection axis oriented in a first direction with respect to the respective adjacent edge, wherein the video imager is configured to supply local motion data in addition to video data proceeding from the light-sensitive cells.