A purpose of the invention is to provide a method and a system for adding or superimposing predetermined pictures, especially advertisement pictures, on predetermined location(s) of moving object(s), especially the clothing of sports players during a match, in a video stream. More generally, the invention aims at superimposing, in a video stream, at least one predetermined image portion at a predetermined location of at least one moving object image, to simulate that the object carries the predetermined image portion on. The disclosure also provides a system for implementing a bidding process to determine which symbols, logos, or messages are overlaid for various simultaneous broadcasts.