Patent ID: 6792128
Filing Date: 2004-09-14
Classification: G06T,H04N

Abstract:
Method of inserting an additional digital signal in digital data corresponding to an image (I), characterised in that it comprises the following steps:detecting (E10) points of interest in said image (I), the points of interest corresponding to some points of the image where bidimensional variations in light intensity are greater than a threshold; selecting (E11) a subset of points of interest (A1, B1, C1) adapted to define a geometric reference frame in said image (I); calculating (E12), for the geometric reference frame, reference information necessary for determining the geometric transformation applied to the image for a class of predetermined geometric transformations; coding (E13) said reference information in a reference key (Kr); and inserting (E16-E19) only the additional digital signal in said digital data.