The present invention relates to a device and a method for displaying images. To combat the copying of images by a camcorder in a cinema auditorium, modulating the luminance of the pixels of a pattern around the value to be displayed to a high frequency which makes the pattern invisible to the human eye but which generates artifacts on the sequence filmed by the camcorder is known. According to the invention, it is proposed to temporally modulate the pattern only in the fixed areas (background or indoor scenes) or, where appropriate, the areas with weak movements. Thus, rather than degrading the image in the areas with movement by applying to them the temporal modulation processing, a decision is taken not to temporally modulate the pattern in these critical areas.