Abstract: A significant change of scene in a gradually changing scene is detected with the aid of at least one camera means (2) for capturing digital images of the scene. A current image (4) of the scene is formed together with a present weighted reference image (6) which is formed from a plurality of previous images (8) of the scene. Cell data is established based on the current image (4) and the present weighted reference image (6). The cell data is statistically analysed so as to be able to identify at least one difference corresponding to a significant change of scene. When identified, an indication of such significant change of scene is provided.