1. A method of determining a second segment ( 108 ) of a second image ( 106 ), with the determining based on a first segment ( 102 ) of a first image ( 100 ), with the first segment ( 102 ) and the second segment ( 108 ) corresponding to an object ( 104 ), characterized in that the method comprises a calculation step to calculate a segment motion model which defines a transformation of the first segment ( 102 ) into the second segment ( 108 ), by comparing values of pixels of the first image ( 100 ) and the second image ( 106 ).