Patent ID: 8919649

Claim:
Method for detecting a marker affixed to a surface of an object, characterized in that it comprises the following operations: a) acquisition ( 40 ) of a photographic image of a scene containing a marker ( 11 ); b) reading the photographic image and detecting ( 50 ) the marker in said scene, this detecting of the marker comprising: c) an extraction of contours in the photographic image, and d) a detection, among these contours, of a contour for positioning the marker corresponding to a set of coplanar conics of a predetermined shape, e) locating ( 60 ) the contour for positioning the marker comprising: f) a modeling of an image of the coplanar conics in matrix form where each conic is represented by a third-order symmetrical matrix, g) an analysis of these matrices to determine a correction of perspective of the photographic image, h) a detection, in the perspective-corrected photographic image, of a fool-proofing element graphically associated with the contour for positioning the marker and correction in rotation of the photographic image, i) detecting, in the perspective-corrected and rotation-corrected photographic image, pieces of encoded data graphically associated with the contour for positioning the marker and decoding ( 70 ) these pieces of encoded data.